Remove trailing '\n' from last-upload-hash branch property.

BUG=None

Review URL: https://chromiumcodereview.appspot.com/14143003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@193943 0039d316-1c4b-4281-b951-d872f2087c98

git_cl.py

@@ -1361,7 +1361,8 @@ def CMDupload(parser, args):
     return GerritUpload(options, args, cl)
   ret = RietveldUpload(options, args, cl)
   if not ret:
-    git_set_branch_value('last-upload-hash', RunGit(['rev-parse', 'HEAD']))
+    git_set_branch_value('last-upload-hash',
+                         RunGit(['rev-parse', 'HEAD']).strip())
 
   return ret