Needed to bring blk-mq uptodate, since changes have been going in
since for-3.14/core was established.

Fixup merge issues related to the immutable biovec changes.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Conflicts:
	block/blk-flush.c
	fs/btrfs/check-integrity.c
	fs/btrfs/extent_io.c
	fs/btrfs/scrub.c
	fs/logfs/dev_bdev.c