ublk: pass queue_limits to blk_mq_alloc_disk

Pass the limits ublk imposes directly to blk_mq_alloc_disk instead of
setting them one at a time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-17-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>