[IPV6]: Per-interface statistics support.

For IP MIB (RFC4293).

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index 34489c1..3ec7d07 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -152,6 +152,7 @@
 
 struct ipv6_devstat {
 	struct proc_dir_entry	*proc_dir_entry;
+	DEFINE_SNMP_STAT(struct ipstats_mib, ipv6);
 	DEFINE_SNMP_STAT(struct icmpv6_mib, icmpv6);
 };