scsi: qedf: 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/20210809230355.8186-36-bvanassche@acm.orgSigned-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qedf/qedf_io.c

@@ -1162,13 +1162,7 @@ void qedf_scsi_completion(struct qedf_ctx *qedf, struct fcoe_cqe *cqe,
 		return;
 	}
 
-	if (!sc_cmd->request) {
-		QEDF_WARN(&(qedf->dbg_ctx), "sc_cmd->request is NULL, "
-		    "sc_cmd=%p.\n", sc_cmd);
-		return;
-	}
-
-	if (!sc_cmd->request->q) {
+	if (!scsi_cmd_to_rq(sc_cmd)->q) {
 		QEDF_WARN(&(qedf->dbg_ctx), "request->q is NULL so request "
 		   "is not valid, sc_cmd=%p.\n", sc_cmd);
 		return;