[NETFILTER]: nf_conntrack: Removes duplicated declarations

These are also in include/net/netfilter/nf_conntrack_helper.h

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>

include/net/netfilter/nf_conntrack.h

@@ -183,13 +183,6 @@ extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 
 extern void nf_conntrack_flush(void);
 
-extern struct nf_conntrack_helper *
-nf_ct_helper_find_get( const struct nf_conntrack_tuple *tuple);
-extern void nf_ct_helper_put(struct nf_conntrack_helper *helper);
-
-extern struct nf_conntrack_helper *
-__nf_conntrack_helper_find_byname(const char *name);
-
 extern int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 				const struct nf_conntrack_tuple *orig);