scsi: ufs: core: Rely on the block layer for setting RQF_PM

scsi: ufs: core: Rely on the block layer for setting RQF_PM

Do not set RQF_PM explicitly since scsi_alloc_request() sets it indirectly
if BLK_MQ_REQ_PM is set. The call chain for the code that sets RQF_PM is as
follows:

    scsi_alloc_request()
      blk_mq_alloc_request()
        __blk_mq_alloc_requests()
          blk_mq_rq_ctx_init()
            if (data->flags & BLK_MQ_REQ_PM)
              data->rq_flags |= RQF_PM;

Link: https://lore.kernel.org/r/20230210193258.4004923-3-bvanassche@acm.org
Cc: Mike Christie <michael.christie@oracle.com>
Cc: John Garry <john.g.garry@oracle.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>