largefiles: rename local variable appropriately

repo['.'] is called not as "working context" but as "parent context".

In this code path, hash value of current content of file should be
compared against hash value recorded in "parent context".

Therefore, "wctx" may cause misunderstanding in this case.

hgext/largefiles/lfutil.py

@@ -165,13 +165,13 b' def openlfdirstate(ui, repo, create=True'
     return lfdirstate
 
 def lfdirstatestatus(lfdirstate, repo):
-    wctx = repo['.']
+    pctx = repo['.']
     match = matchmod.always(repo.root, repo.getcwd())
     unsure, s = lfdirstate.status(match, [], False, False, False)
     modified, clean = s.modified, s.clean
     for lfile in unsure:
         try:
-            fctx = wctx[standin(lfile)]
+            fctx = pctx[standin(lfile)]
         except LookupError:
             fctx = None
         if not fctx or fctx.data().strip() != hashfile(repo.wjoin(lfile)):