blk-mq: move the !async handling out of __blk_mq_delay_run_hw_queue

Only blk_mq_run_hw_queue can call __blk_mq_delay_run_hw_queue with
async=false, so move the handling there.

With this __blk_mq_delay_run_hw_queue can be merged into
blk_mq_delay_run_hw_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230413060651.694656-5-hch@lst.de


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