[IPV6]: Optimize hop-limit determination.

Last part of hop-limit determination is always:
    hoplimit = dst_metric(dst, RTAX_HOPLIMIT);
    if (hoplimit < 0)
        hoplimit = ipv6_get_hoplimit(dst->dev).

Let's consolidate it as ip6_dst_hoplimit(dst).

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index 232da20..edcb4bb 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -123,8 +123,6 @@
 
 extern void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len);
 
-extern int ipv6_get_hoplimit(struct net_device *dev);
-
 /*
  *	anycast prototypes (anycast.c)
  */
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 0e2895c..5c3b67c 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -88,6 +88,8 @@
 					   const struct in6_addr *addr,
 					   int anycast);
 
+extern int			ip6_dst_hoplimit(struct dst_entry *dst);
+
 /*
  *	support functions for ND
  *