netfilter: ip_tables: remove unused function declarations.

Two headers include declarations of functions which are never defined.
Remove them.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/linux/netfilter_ipv4/ip_tables.h

@@ -23,8 +23,6 @@
 #include <linux/init.h>
 #include <uapi/linux/netfilter_ipv4/ip_tables.h>
 
-extern void ipt_init(void) __init;
-
 #if IS_ENABLED(CONFIG_NETFILTER)
 int ipt_register_table(struct net *net, const struct xt_table *table,
 		       const struct ipt_replace *repl,

include/linux/netfilter_ipv6/ip6_tables.h

@@ -23,9 +23,8 @@
 #include <linux/init.h>
 #include <uapi/linux/netfilter_ipv6/ip6_tables.h>
 
-extern void ip6t_init(void) __init;
-
 extern void *ip6t_alloc_initial_table(const struct xt_table *);
+
 #if IS_ENABLED(CONFIG_NETFILTER)
 int ip6t_register_table(struct net *net, const struct xt_table *table,
 			const struct ip6t_replace *repl,