UPSTREAM: scsi: ufs: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. This patch does not change any functionality.

Link: https://lore.kernel.org/r/20210809230355.8186-48-bvanassche@acm.org


Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Bug: 204438323
(cherry picked from commit 3f2c1002)
Signed-off-by: Bart Van Assche <bvanassche@google.com>
Change-Id: Ia097ab3da630dcadd70fb8efbfd212e60cfcc79c