Fixed a long and complex line by breaking into a for loop, with the added...

Fixed a long and complex line by breaking into a for loop, with the added benefit that the method will now exit as soon as a matching 
permission is found instead of checking all of the user's permissions and putting them into a temporary list.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@7823 bcc190cf-cafb-0310-a4f2-bffc1f526a37