net: Abstract dst->neighbour accesses behind helpers.

dst_{get,set}_neighbour()

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 48cd03d..a06c53c 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -656,7 +656,7 @@
 	 * layer address of our nexhop router
 	 */
 
-	if (rt->dst.neighbour == NULL)
+	if (dst_get_neighbour(&rt->dst) == NULL)
 		ifa->flags &= ~IFA_F_OPTIMISTIC;
 
 	ifa->idev = idev;