Merge tag 'upstream-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs

Pull UBI and UBIFS updates from Richard Weinberger:

 - A new interface for UBI to deal better with read disturb

 - Reject unsupported ioctl flags in UBIFS (xfstests found it)

* tag 'upstream-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  ubi: wl: Silence uninitialized variable warning
  ubifs: Reject unsupported ioctl flags explicitly
  ubi: Expose the bitrot interface
  ubi: Introduce in_pq()