tc: u32: Fix icmp_code off.

The off of icmp_code is not 20 but 21. Also offmask should be 0 unless
nexthdr+ is specified.

Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
diff --git a/tc/f_u32.c b/tc/f_u32.c
index 975c0b5..7a04634 100644
--- a/tc/f_u32.c
+++ b/tc/f_u32.c
@@ -531,7 +531,7 @@
 		res = parse_u8(&argc, &argv, sel, 20, 0);
 	} else if (strcmp(*argv, "icmp_code") == 0) {
 		NEXT_ARG();
-		res = parse_u8(&argc, &argv, sel, 20, 1);
+		res = parse_u8(&argc, &argv, sel, 21, 0);
 	} else
 		return -1;