patches: improve fixes fetch

The fixes check should be against the current branch or alternatively your own master branch. But I think the current branch is fine. linus/master is missing lots of patches that are in media-master, so it would fail on such checks. 12:41 And I just get "WARNING: Unknown commit id '78b3f9d75a63', maybe rebased or not pulled?" if a commit id is not found, not a weird fatal error. 12:42