uncommit: use ctx1.status(ctx2) instead of repo.status(ctx1, ctx2)

Differential Revision: https://phab.mercurial-scm.org/D3998

hgext/uncommit.py

@@ -182,7 +182,7 b' def uncommit(ui, repo, *pats, **opts):'
 
             with repo.dirstate.parentchange():
                 repo.dirstate.setparents(newid, node.nullid)
-                s = repo.status(old.p1(), old, match=match)
+                s = old.p1().status(old, match=match)
                 _fixdirstate(repo, old, repo[newid], s)
 
 def predecessormarkers(ctx):