scsi: qedi: 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/20210809230355.8186-37-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qedi/qedi_fw.c

@@ -609,14 +609,7 @@ static void qedi_scsi_completion(struct qedi_ctx *qedi,
 		goto error;
 	}
 
-	if (!sc_cmd->request) {
-		QEDI_WARN(&qedi->dbg_ctx,
-			  "sc_cmd->request is NULL, sc_cmd=%p.\n",
-			  sc_cmd);
-		goto error;
-	}
-
-	if (!sc_cmd->request->q) {
+	if (!scsi_cmd_to_rq(sc_cmd)->q) {
 		QEDI_WARN(&qedi->dbg_ctx,
 			  "request->q is NULL so request is not valid, sc_cmd=%p.\n",
 			  sc_cmd);