tests: fix a bug in `f` that prevented calculating sha1sum on a file

tests/f

@@ -59,7 +59,7 b' def visit(opts, filenames, outfile):'
         if isfile:
             if opts.type:
                 facts.append('file')
-            if opts.hexdump or opts.dump or opts.md5:
+            if opts.hexdump or opts.dump or opts.md5 or opts.sha1:
                 content = open(f, 'rb').read()
         elif islink:
             if opts.type:

tests/test-tools.t

@@ -38,6 +38,9 b' Tests of the file helper tool'
   $ f foo
   foo:
 
+  $ f --sha1 foo
+  foo: sha1=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15
+
 #if symlink
   $ f foo --mode
   foo: mode=644