tc: allow qdisc without options

Pfifo_fast needs no options. So don't force it to have parsing code.

tc/tc_qdisc.c

@@ -137,15 +137,15 @@ static int tc_qdisc_modify(int cmd, unsigned flags, int argc, char **argv)
 	if (est.ewma_log)
 		addattr_l(&req.n, sizeof(req), TCA_RATE, &est, sizeof(est));
 
-	if (q) {
-		if (!q->parse_qopt) {
-			fprintf(stderr, "qdisc '%s' does not support option parsing\n", k);
-			return -1;
-		}
-		if (q->parse_qopt(q, argc, argv, &req.n))
-			return 1;
-	} else {
-		if (argc) {
+	if (argc) {
+		if (q) {
+			if (!q->parse_qopt) {
+				fprintf(stderr, "qdisc '%s' does not support option parsing\n", k);
+				return -1;
+			}
+			if (q->parse_qopt(q, argc, argv, &req.n))
+				return 1;
+		} else {
 			if (matches(*argv, "help") == 0)
 				usage();