blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request

blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request

BugLink: https://bugs.launchpad.net/bugs/1848739
After commit:

923218f6166a ("blk-mq: don't allocate driver tag upfront for flush rq")

we no longer use the 'can_block' argument in
blk_mq_sched_insert_request(). Kill it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Added actual commit message as to why it's being removed.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit 9e97d2951a7e6ee6e204f87f6bda4ff754a8cede)
[marcelo.cerri@canonical.com: fixed conflict in blk_mq_requeue_work()
 because the commit aef1897cd36d ("blk-mq: insert rq with DONTPREP to
 hctx dispatch list when requeue") was already applied]
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>