ipv6: Preserve pervious behavior in ipv6_link_dev_addr().

Use list_add_tail() to get the behavior we had before
the list_head conversion for ipv6 address lists.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 68e5809..9995683 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -578,7 +578,7 @@
 			break;
 	}
 
-	list_add(&ifp->if_list, p);
+	list_add_tail(&ifp->if_list, p);
 }
 
 static u32 ipv6_addr_hash(const struct in6_addr *addr)