scsi: core: Use rq_dma_dir in scsi_setup_cmnd()

Link: https://lore.kernel.org/r/20201005084130.143273-6-hch@lst.de
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_lib.c

@@ -1215,12 +1215,7 @@ static blk_status_t scsi_setup_cmnd(struct scsi_device *sdev,
 	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
 	blk_status_t ret;
 
-	if (!blk_rq_bytes(req))
-		cmd->sc_data_direction = DMA_NONE;
-	else if (rq_data_dir(req) == WRITE)
-		cmd->sc_data_direction = DMA_TO_DEVICE;
-	else
-		cmd->sc_data_direction = DMA_FROM_DEVICE;
+	cmd->sc_data_direction = rq_dma_dir(req);
 
 	if (blk_rq_is_scsi(req))
 		ret = scsi_setup_scsi_cmnd(sdev, req);