[NETFILTER]: x_tables: error if ip_conntrack is asked to handle IPv6 packets

To do that, this makes nf_ct_l3proto_try_module_{get,put} compatible
functions. As a result we can remove '#ifdef' surrounds and direct call of
need_conntrack().

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c
index 0ea501a..3dc2357 100644
--- a/net/netfilter/xt_conntrack.c
+++ b/net/netfilter/xt_conntrack.c
@@ -20,6 +20,7 @@
 
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter/xt_conntrack.h>
+#include <net/netfilter/nf_conntrack_compat.h>
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
@@ -228,21 +229,17 @@
 	   void *matchinfo,
 	   unsigned int hook_mask)
 {
-#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 	if (nf_ct_l3proto_try_module_get(match->family) < 0) {
-		printk(KERN_WARNING "can't load nf_conntrack support for "
+		printk(KERN_WARNING "can't load conntrack support for "
 				    "proto=%d\n", match->family);
 		return 0;
 	}
-#endif
 	return 1;
 }
 
 static void destroy(const struct xt_match *match, void *matchinfo)
 {
-#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 	nf_ct_l3proto_module_put(match->family);
-#endif
 }
 
 static struct xt_match conntrack_match = {
@@ -257,7 +254,6 @@
 
 static int __init xt_conntrack_init(void)
 {
-	need_conntrack();
 	return xt_register_match(&conntrack_match);
 }