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_comment.c b/net/netfilter/xt_comment.c
index bd7aa57..e821798 100644
--- a/net/netfilter/xt_comment.c
+++ b/net/netfilter/xt_comment.c
@@ -22,31 +22,23 @@
 	return true;
 }
 
-static struct xt_match comment_mt_reg[] __read_mostly = {
-	{
-		.name		= "comment",
-		.family		= NFPROTO_IPV4,
-		.match		= comment_mt,
-		.matchsize	= sizeof(struct xt_comment_info),
-		.me		= THIS_MODULE
-	},
-	{
-		.name		= "comment",
-		.family		= NFPROTO_IPV6,
-		.match		= comment_mt,
-		.matchsize	= sizeof(struct xt_comment_info),
-		.me		= THIS_MODULE
-	},
+static struct xt_match comment_mt_reg __read_mostly = {
+	.name      = "comment",
+	.revision  = 0,
+	.family    = NFPROTO_UNSPEC,
+	.match     = comment_mt,
+	.matchsize = sizeof(struct xt_comment_info),
+	.me        = THIS_MODULE,
 };
 
 static int __init comment_mt_init(void)
 {
-	return xt_register_matches(comment_mt_reg, ARRAY_SIZE(comment_mt_reg));
+	return xt_register_match(&comment_mt_reg);
 }
 
 static void __exit comment_mt_exit(void)
 {
-	xt_unregister_matches(comment_mt_reg, ARRAY_SIZE(comment_mt_reg));
+	xt_unregister_match(&comment_mt_reg);
 }
 
 module_init(comment_mt_init);