scsi: aha1542: 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/20210809230355.8186-16-bvanassche@acm.org
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/aha1542.c

@@ -262,11 +262,12 @@ static void aha1542_free_cmd(struct scsi_cmnd *cmd)
 	struct aha1542_cmd *acmd = scsi_cmd_priv(cmd);
 
 	if (cmd->sc_data_direction == DMA_FROM_DEVICE) {
+		struct request *rq = scsi_cmd_to_rq(cmd);
 		void *buf = acmd->data_buffer;
 		struct req_iterator iter;
 		struct bio_vec bv;
 
-		rq_for_each_segment(bv, cmd->request, iter) {
+		rq_for_each_segment(bv, rq, iter) {
 			memcpy_to_page(bv.bv_page, bv.bv_offset, buf,
 				       bv.bv_len);
 			buf += bv.bv_len;
@@ -447,11 +448,12 @@ static int aha1542_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
 #endif
 
 	if (cmd->sc_data_direction == DMA_TO_DEVICE) {
+		struct request *rq = scsi_cmd_to_rq(cmd);
 		void *buf = acmd->data_buffer;
 		struct req_iterator iter;
 		struct bio_vec bv;
 
-		rq_for_each_segment(bv, cmd->request, iter) {
+		rq_for_each_segment(bv, rq, iter) {
 			memcpy_from_page(buf, bv.bv_page, bv.bv_offset,
 					 bv.bv_len);
 			buf += bv.bv_len;