netfilter: revert a2361c8

This patch reverts a2361c8:
"[PATCH] netfilter: xt_conntrack: warn about use in raw table"

Florian Wesphal says:
"... when the packet was sent from the local machine the skb
already has ->nfct attached, and -m conntrack seems to do
the right thing."

Acked-by: Jan Engelhardt <jengelh@medozas.de>
Reported-by: Florian Wesphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/xt_conntrack.c

@@ -272,11 +272,6 @@ static int conntrack_mt_check(const struct xt_mtchk_param *par)
 {
 	int ret;
 
-	if (strcmp(par->table, "raw") == 0) {
-		pr_info("state is undetermined at the time of raw table\n");
-		return -EINVAL;
-	}
-
 	ret = nf_ct_l3proto_try_module_get(par->family);
 	if (ret < 0)
 		pr_info("cannot load conntrack support for proto=%u\n",