block: introduce blk_queue_rot()

block: introduce blk_queue_rot()

To check if a request queue is for a rotational device, a double
negation is needed with the pattern "!blk_queue_nonrot(q)". Simplify
this with the introduction of the helper blk_queue_rot() which tests
if a requests queue limit has the BLK_FEAT_ROTATIONAL feature set.
All call sites of blk_queue_nonrot() are modified to use blk_queue_rot()
and blk_queue_nonrot() definition removed.

No functional changes.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>