verify: clean up weird error/warning lists

verify: clean up weird error/warning lists

Nested functions in Python are not able to assign to variables in the
outer scope without something like the list trick because assignments
refer to the inner scope. So, we formerly used a list to give an
object to assign into.

Now that error and warning are object members, the [0] hack is no
longer needed.

--- a/mercurial/verify.py	Fri Dec 18 18:52:25 2015 +0000
+++ b/mercurial/verify.py	Sun Dec 20 16:33:44 2015 -0600
@@ -51,8 +51,8 @@
         self.repo = repo.unfiltered()
         self.ui = repo.ui
         self.badrevs = set()
-        self.errors = [0]
-        self.warnings = [0]
+        self.errors = 0
+        self.warnings = 0
         self.havecl = len(repo.changelog) > 0
         self.havemf = len(repo.manifest) > 0
         self.revlogv1 = repo.changelog.version != revlog.REVLOGV0
@@ -62,7 +62,7 @@
 
     def warn(self, msg):
         self.ui.warn(msg + "\n")
-        self.warnings[0] += 1
+        self.warnings += 1
 
     def err(self, linkrev, msg, filename=None):
         if linkrev is not None:
@@ -73,7 +73,7 @@
         if filename:
             msg = "%s@%s" % (filename, msg)
         self.ui.warn(" " + msg + "\n")
-        self.errors[0] += 1
+        self.errors += 1
 
     def exc(self, linkrev, msg, inst, filename=None):
         if not str(inst):
@@ -87,8 +87,6 @@
         filenodes = {}
         revisions = 0
         badrevs = self.badrevs
-        errors = self.errors
-        warnings = self.warnings
         ui = repo.ui
         cl = repo.changelog
         mf = repo.manifest
@@ -352,13 +350,13 @@
 
         ui.status(_("%d files, %d changesets, %d total revisions\n") %
                        (len(files), len(cl), revisions))
-        if warnings[0]:
-            ui.warn(_("%d warnings encountered!\n") % warnings[0])
+        if self.warnings:
+            ui.warn(_("%d warnings encountered!\n") % self.warnings)
         if self.fncachewarned:
             ui.warn(_('hint: run "hg debugrebuildfncache" to recover from '
                       'corrupt fncache\n'))
-        if errors[0]:
-            ui.warn(_("%d integrity errors encountered!\n") % errors[0])
+        if self.errors:
+            ui.warn(_("%d integrity errors encountered!\n") % self.errors)
             if badrevs:
                 ui.warn(_("(first damaged changeset appears to be %d)\n")
                         % min(badrevs))