netfilter: xtables: use NFPROTO_UNSPEC in more extensions

Lots of extensions are completely family-independent, so squash some code.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/netfilter/xt_realm.c b/net/netfilter/xt_realm.c
index b259421..6741928 100644
--- a/net/netfilter/xt_realm.c
+++ b/net/netfilter/xt_realm.c
@@ -36,7 +36,7 @@
 	.matchsize	= sizeof(struct xt_realm_info),
 	.hooks		= (1 << NF_INET_POST_ROUTING) | (1 << NF_INET_FORWARD) |
 			  (1 << NF_INET_LOCAL_OUT) | (1 << NF_INET_LOCAL_IN),
-	.family		= NFPROTO_IPV4,
+	.family		= NFPROTO_UNSPEC,
 	.me		= THIS_MODULE
 };