patch: fix sort() comparator argument

'hg import' fails under Python 2.3. The name of the compare function parameter in the call to list.sort() is 'cmpfunc' in Python 2.3 and
'cmp' in Python 2.4+. Passing the compare function as a named parameter is therefore problematic.

mercurial/patch.py

@@ -357,7 +357,7 b' class patchfile:'
 
         if len(cand) > 1:
             # resort our list of potentials forward then back.
-            cand.sort(cmp=sorter)
+            cand.sort(sorter)
         return cand
 
     def hashlines(self):