Remove WindowsError reference on non-windows systems

Lib/shutil.py

 """Utility functions for copying files and directory trees.
 
 XXX The functions here don't copy the resource fork or other metadata on Mac.
 
 """
 
 import os
 import sys
 import stat
 from os.path import abspath
@@ skipping 119 matching lines @@
             # XXX What about devices, sockets etc.?
         except (IOError, os.error), why:
             errors.append((srcname, dstname, str(why)))
         # catch the Error from the recursive copytree so that we can
         # continue with other files
         except Error, err:
             errors.extend(err.args[0])
     try:
         copystat(src, dst)
     except OSError, why:
-        if WindowsError is not None and isinstance(err, WindowsError):
+        if WindowsError is not None and isinstance(why, WindowsError):
             # Copying file access times may fail on Windows
             pass
         else:
             errors.extend((src, dst, str(why)))
     if errors:
         raise Error, errors
 
 def rmtree(path, ignore_errors=False, onerror=None):
     """Recursively delete a directory tree.
 
@@ skipping 77 matching lines @@
             if destinsrc(src, dst):
                 raise Error, "Cannot move a directory '%s' into itself '%s'." % (src, dst)
             copytree(src, real_dst, symlinks=True)
             rmtree(src)
         else:
             copy2(src, real_dst)
             os.unlink(src)
 
 def destinsrc(src, dst):
     return abspath(dst).startswith(abspath(src))