[PATCH 3 of 4] debugcommands: use repo[None].walk instead of repo.walk

[Augie Fackler]

# HG changeset patch
# User Augie Fackler <augie at google.com>
# Date 1495144861 14400
#      Thu May 18 18:01:01 2017 -0400
# Node ID d915f006acf67a7f8f57526a697f498cea3830cc
# Parent  fbe9d489a31ebac315164fbbb11989ab48faee43
debugcommands: use repo[None].walk instead of repo.walk

diff --git a/mercurial/debugcommands.py b/mercurial/debugcommands.py
--- a/mercurial/debugcommands.py
+++ b/mercurial/debugcommands.py
@@ -2167,7 +2167,7 @@ def debugupgraderepo(ui, repo, run=False
 def debugwalk(ui, repo, *pats, **opts):
     """show how files match on given patterns"""
     m = scmutil.match(repo[None], pats, opts)
-    items = list(repo.walk(m))
+    items = list(repo[None].walk(m))
     if not items:
         return
     f = lambda fn: fn