Fixed #14550 -- fixed the behavior of commit_on_success to exit the transaction properly.  This was a bug introduced in [14288].  Thanks to Justin for the report and Florian Apolloner for help debugging.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14343 bcc190cf-cafb-0310-a4f2-bffc1f526a37