changegroup: don't use 'repo' for non-repo 'self'

'repo' is a very confusing name to use for 'self', especially when
it's not a repo. Also drop repo.ui member (a.k.a. self.ui) now that
'self' doesn't shadow outer 'repo' variable.

mercurial/changegroup.py

@@ -743,12 +743,11 b' def addchangegroup(repo, source, srctype'
         class prog(object):
             step = _('changesets')
             count = 1
-            ui = repo.ui
             total = expectedtotal
-            def __call__(repo):
-                repo.ui.progress(repo.step, repo.count, unit=_('chunks'),
-                                 total=repo.total)
-                repo.count += 1
+            def __call__(self):
+                repo.ui.progress(self.step, self.count, unit=_('chunks'),
+                                 total=self.total)
+                self.count += 1
         pr = prog()
         source.callback = pr