tc: u32: Fix firstfrag filter.

On current firstfrag filter, all non fragmented packets are matched.
firstfrag should check MF bit.

Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
diff --git a/tc/f_u32.c b/tc/f_u32.c
index 7a04634..66c3247 100644
--- a/tc/f_u32.c
+++ b/tc/f_u32.c
@@ -513,7 +513,7 @@
 		res = pack_key16(sel, 0, 0x3FFF, 6, 0);
 	} else if (strcmp(*argv, "firstfrag") == 0) {
 		argc--; argv++;
-		res = pack_key16(sel, 0, 0x1FFF, 6, 0);
+		res = pack_key16(sel, 0x2000, 0x3FFF, 6, 0);
 	} else if (strcmp(*argv, "df") == 0) {
 		argc--; argv++;
 		res = pack_key16(sel, 0x4000, 0x4000, 6, 0);