Pull UBI/UBIFS updates from Richard Weinberger:
"This contains three changes - two cleanups and one UBI wear leveling
improvement by Sebastian Siewior"
* tag 'upstream-4.5-rc1' of git://git.infradead.org/linux-ubifs:
ubifs: Use XATTR_*_PREFIX_LEN
UBIFS: add a comment in key.h for unused parameter
mtd: ubi: wl: avoid erasing a PEB which is empty