Fix git-freeze when using a commit hook which could reject a commit.

This prevents `git rebase-update` from losing work when using a hook like
pre-commit-go.

R=dnj@chromium.org, vadimsh@chromium.org, maruel@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1350043002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@296737 0039d316-1c4b-4281-b951-d872f2087c98

git_common.py

@@ -357,14 +357,14 @@ def freeze():
   took_action = False
 
   try:
-    run('commit', '-m', FREEZE + '.indexed')
+    run('commit', '--no-verify', '-m', FREEZE + '.indexed')
     took_action = True
   except subprocess2.CalledProcessError:
     pass
 
   try:
     run('add', '-A')
-    run('commit', '-m', FREEZE + '.unindexed')
+    run('commit', '--no-verify', '-m', FREEZE + '.unindexed')
     took_action = True
   except subprocess2.CalledProcessError:
     pass