Fix for git-svn rebase bug

git-svn rebase will always output 'Current branch <> is up-to-date' when the
branch is up-to-date, even if you pass the --quiet flag(s). This change
specifically squelches that message.

Review URL: http://codereview.chromium.org/555183

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@37696 0039d316-1c4b-4281-b951-d872f2087c98

gclient

@@ -44,7 +44,11 @@ if [ "X$DEPOT_TOOLS_UPDATE" != "X0" -a -e "$base_dir/.git" ]
 then
   cd $base_dir
   test_git_svn
-  git svn rebase -q -q
+  # work around a git-svn --quiet bug
+  OUTPUT=`git svn rebase -q -q`
+  if [[ ! "$OUTPUT" =~ Current.branch ]]; then
+    echo $OUTPUT
+  fi
   cd - > /dev/null
 fi