Fixed test failure that was occurring since r12908

The tests were relying on being able to do
ManyToManyField("NameOfThisModel") instead of the only documented method for
recursive relationships, namely ManyToManyField("self").  The former stopped
working when the fix in r12908 was applied.



git-svn-id: http://code.djangoproject.com/svn/django/trunk@12932 bcc190cf-cafb-0310-a4f2-bffc1f526a37