tests: remove unused import from 'f' utility

It should have been caught by pyflakes.

tests/f

@@ -1,165 +1,164 b''
 #!/usr/bin/env python
 
 """
 Utility for inspecting files in various ways.
 
 This tool is like the collection of tools found in a unix environment but are
 cross platform and stable and suitable for our needs in the test suite.
 
 This can be used instead of tools like:
   [
   dd
   find
   head
   hexdump
   ls
   md5sum
   readlink
   sha1sum
   stat
   tail
   test
   readlink.py
   md5sum.py
 """
 
 from __future__ import absolute_import
 
-import errno
 import glob
 import optparse
 import os
 import re
 import sys
 
 def visit(opts, filenames, outfile):
     """Process filenames in the way specified in opts, writing output to
     outfile."""
     for f in sorted(filenames):
         isstdin = f == '-'
         if not isstdin and not os.path.lexists(f):
             outfile.write('%s: file not found\n' % f)
             continue
         quiet = opts.quiet and not opts.recurse or isstdin
         isdir = os.path.isdir(f)
         islink = os.path.islink(f)
         isfile = os.path.isfile(f) and not islink
         dirfiles = None
         content = None
         facts = []
         if isfile:
             if opts.type:
                 facts.append('file')
             if opts.hexdump or opts.dump or opts.md5:
                 content = file(f, 'rb').read()
         elif islink:
             if opts.type:
                 facts.append('link')
             content = os.readlink(f)
         elif isstdin:
             content = sys.stdin.read()
             if opts.size:
                 facts.append('size=%s' % len(content))
         elif isdir:
             if opts.recurse or opts.type:
                 dirfiles = glob.glob(f + '/*')
                 facts.append('directory with %s files' % len(dirfiles))
         elif opts.type:
             facts.append('type unknown')
         if not isstdin:
             stat = os.lstat(f)
             if opts.size and not isdir:
                 facts.append('size=%s' % stat.st_size)
             if opts.mode and not islink:
                 facts.append('mode=%o' % (stat.st_mode & 0o777))
             if opts.links:
                 facts.append('links=%s' % stat.st_nlink)
             if opts.newer:
                 # mtime might be in whole seconds so newer file might be same
                 if stat.st_mtime >= os.stat(opts.newer).st_mtime:
                     facts.append('newer than %s' % opts.newer)
                 else:
                     facts.append('older than %s' % opts.newer)
         if opts.md5 and content is not None:
             try:
                 from hashlib import md5
             except ImportError:
                 from md5 import md5
             facts.append('md5=%s' % md5(content).hexdigest()[:opts.bytes])
         if opts.sha1 and content is not None:
             try:
                 from hashlib import sha1
             except ImportError:
                 from sha import sha as sha1
             facts.append('sha1=%s' % sha1(content).hexdigest()[:opts.bytes])
         if isstdin:
             outfile.write(', '.join(facts) + '\n')
         elif facts:
             outfile.write('%s: %s\n' % (f, ', '.join(facts)))
         elif not quiet:
             outfile.write('%s:\n' % f)
         if content is not None:
             chunk = content
             if not islink:
                 if opts.lines:
                     if opts.lines >= 0:
                         chunk = ''.join(chunk.splitlines(True)[:opts.lines])
                     else:
                         chunk = ''.join(chunk.splitlines(True)[opts.lines:])
                 if opts.bytes:
                     if opts.bytes >= 0:
                         chunk = chunk[:opts.bytes]
                     else:
                         chunk = chunk[opts.bytes:]
             if opts.hexdump:
                 for i in range(0, len(chunk), 16):
                     s = chunk[i:i + 16]
                     outfile.write('%04x: %-47s |%s|\n' %
                                   (i, ' '.join('%02x' % ord(c) for c in s),
                                    re.sub('[^ -~]', '.', s)))
             if opts.dump:
                 if not quiet:
                     outfile.write('>>>\n')
                 outfile.write(chunk)
                 if not quiet:
                     if chunk.endswith('\n'):
                         outfile.write('<<<\n')
                     else:
                         outfile.write('\n<<< no trailing newline\n')
         if opts.recurse and dirfiles:
             assert not isstdin
             visit(opts, dirfiles, outfile)
 
 if __name__ == "__main__":
     parser = optparse.OptionParser("%prog [options] [filenames]")
     parser.add_option("-t", "--type", action="store_true",
                       help="show file type (file or directory)")
     parser.add_option("-m", "--mode", action="store_true",
                       help="show file mode")
     parser.add_option("-l", "--links", action="store_true",
                       help="show number of links")
     parser.add_option("-s", "--size", action="store_true",
                       help="show size of file")
     parser.add_option("-n", "--newer", action="store",
                       help="check if file is newer (or same)")
     parser.add_option("-r", "--recurse", action="store_true",
                       help="recurse into directories")
     parser.add_option("-S", "--sha1", action="store_true",
                       help="show sha1 hash of the content")
     parser.add_option("-M", "--md5", action="store_true",
                       help="show md5 hash of the content")
     parser.add_option("-D", "--dump", action="store_true",
                       help="dump file content")
     parser.add_option("-H", "--hexdump", action="store_true",
                       help="hexdump file content")
     parser.add_option("-B", "--bytes", type="int",
                       help="number of characters to dump")
     parser.add_option("-L", "--lines", type="int",
                       help="number of lines to dump")
     parser.add_option("-q", "--quiet", action="store_true",
                       help="no default output")
     (opts, filenames) = parser.parse_args(sys.argv[1:])
     if not filenames:
         filenames = ['-']
 
     visit(opts, filenames, sys.stdout)