src: use NFPROTO_ constants

Resync netfilter.h from the latest kernel and make use of the new
NFPROTO_ constants that have been introduced.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/extensions/libxt_tcp.c b/extensions/libxt_tcp.c
index a720ba4..14d8c18 100644
--- a/extensions/libxt_tcp.c
+++ b/extensions/libxt_tcp.c
@@ -378,7 +378,7 @@
 }
 
 static struct xtables_match tcp_match = {
-	.family		= AF_INET,
+	.family		= NFPROTO_IPV4,
 	.name		= "tcp",
 	.version	= XTABLES_VERSION,
 	.size		= XT_ALIGN(sizeof(struct xt_tcp)),
@@ -392,7 +392,7 @@
 };
 
 static struct xtables_match tcp_match6 = {
-	.family		= AF_INET6,
+	.family		= NFPROTO_IPV6,
 	.name		= "tcp",
 	.version	= XTABLES_VERSION,
 	.size		= XT_ALIGN(sizeof(struct xt_tcp)),