[NET]: Fix sparse warnings

Of this type, mostly:

CHECK   net/ipv6/netfilter.c
net/ipv6/netfilter.c:96:12: warning: symbol 'ipv6_netfilter_init' was not declared. Should it be static?
net/ipv6/netfilter.c:101:6: warning: symbol 'ipv6_netfilter_fini' was not declared. Should it be static?

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index b5b58e9..fc2d4c8 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -110,6 +110,8 @@
 {
 	return (struct ethhdr *)skb->mac.raw;
 }
+
+extern struct ctl_table ether_table[];
 #endif
 
 #endif	/* _LINUX_IF_ETHER_H */