xen-blkfront: don't redundantly set max_sements in blkif_recover

blkif_set_queue_limits already sets the max_sements limits, so don't do
it a second time.  Also remove a comment about a long fixe bug in
blk_mq_update_nr_hw_queues.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Link: https://lore.kernel.org/r/20240221125845.3610668-4-hch@lst.de


Signed-off-by: Jens Axboe <axboe@kernel.dk>