scsi: ibmvfc: 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/20210809230355.8186-24-bvanassche@acm.orgSigned-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ibmvscsi/ibmvfc.c

@@ -1911,7 +1911,7 @@ static int ibmvfc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *cmnd)
 	struct ibmvfc_cmd *vfc_cmd;
 	struct ibmvfc_fcp_cmd_iu *iu;
 	struct ibmvfc_event *evt;
-	u32 tag_and_hwq = blk_mq_unique_tag(cmnd->request);
+	u32 tag_and_hwq = blk_mq_unique_tag(scsi_cmd_to_rq(cmnd));
 	u16 hwq = blk_mq_unique_tag_to_hwq(tag_and_hwq);
 	u16 scsi_channel;
 	int rc;