largefiles: fix 'hg clone . ../foo' OSError abort

Operating on a non-existant file can cause both IOError and OSError,
depending on the function used: open raises IOError, os.lstat raises
OSError.

The largefiles code called dirstate.normal, which in turn calls
os.lstat, so OSError is the right exception to catch here.

hgext/largefiles/lfutil.py

@@ -158,7 +158,7 b' def openlfdirstate(ui, repo):'
             try:
                 if hash == hashfile(lfile):
                     lfdirstate.normal(lfile)
-            except IOError, err:
+            except OSError, err:
                 if err.errno != errno.ENOENT:
                     raise
 

tests/test-largefiles.t

@@ -252,13 +252,12 b' dir after a purge.'
 
 Clone a largefiles repo.
 
-  $ cd ..
-  $ hg clone a b
+  $ hg clone . ../b
   updating to branch default
   5 files updated, 0 files merged, 0 files removed, 0 files unresolved
   getting changed largefiles
   3 largefiles updated, 0 removed
-  $ cd b
+  $ cd ../b
   $ hg log --template '{rev}:{node|short}  {desc|firstline}\n'
   7:daea875e9014  add/edit more largefiles
   6:4355d653f84f  edit files yet again