Merge tag 'upstream-4.8-rc4' of git://git.infradead.org/linux-ubifs

Pull UBIFS fixes from Richard Weinberger:
 "This pull requests contains fixes for two issues in UBI and UBIFS:

   - wrong UBIFS assertion.
   - a UBIFS xattr regression"

* tag 'upstream-4.8-rc4' of git://git.infradead.org/linux-ubifs:
  ubifs: Fix xattr generic handler usage
  ubifs: Fix assertion in layout_in_gaps()