Merge tag 'upstream-4.3-rc4' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS fixes from Richard Weinberger:
 "This contains three bug fixes for both UBI and UBIFS"

* tag 'upstream-4.3-rc4' of git://git.infradead.org/linux-ubifs:
  UBI: return ENOSPC if no enough space available
  UBI: Validate data_size
  UBIFS: Kill unneeded locking in ubifs_init_security