rnbd-clt: pass queue_limits to blk_mq_alloc_disk

rnbd-clt: pass queue_limits to blk_mq_alloc_disk

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

While at it don't set an explicit number of discard segments, as 1 is
the default (which most drivers rely on).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20240215070300.2200308-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>