[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/net/ipv6/route.c b/net/ipv6/route.c
index 6ea494a..5d5bbb4 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1372,7 +1372,7 @@
  *	Drop the packet on the floor
  */
 
-int ip6_pkt_discard(struct sk_buff *skb)
+static int ip6_pkt_discard(struct sk_buff *skb)
 {
 	IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_NOROUTE, 0, skb->dev);
@@ -1380,7 +1380,7 @@
 	return 0;
 }
 
-int ip6_pkt_discard_out(struct sk_buff *skb)
+static int ip6_pkt_discard_out(struct sk_buff *skb)
 {
 	skb->dev = skb->dst->dev;
 	return ip6_pkt_discard(skb);
@@ -1960,8 +1960,6 @@
 	return arg.len;
 }
 
-extern struct rt6_statistics rt6_stats;
-
 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
 {
 	seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",