netfilter: remove dead code

Remove __nf_conntrack_find() from headers.

Fixes: dcd93ed4cd1 ("netfilter: nf_conntrack: remove dead code")
Signed-off-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_conntrack.h

@@ -183,10 +183,6 @@ void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
 
 void nf_ct_free_hashtable(void *hash, unsigned int size);
 
-struct nf_conntrack_tuple_hash *
-__nf_conntrack_find(struct net *net, u16 zone,
-		    const struct nf_conntrack_tuple *tuple);
-
 int nf_conntrack_hash_check_insert(struct nf_conn *ct);
 bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);