ipv6: fib: Convert fib6_age() to dst_neigh_lookup().

In this specific situation we know we are dealing with a gatewayed route
and therefore rt6i_gateway is not going to be in6addr_any even in future
interpretations.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/ip6_fib.c

@@ -1552,11 +1552,20 @@ static int fib6_age(struct rt6_info *rt, void *arg)
 		    time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
 			RT6_TRACE("aging clone %p\n", rt);
 			return -1;
-		} else if ((rt->rt6i_flags & RTF_GATEWAY) &&
-			   (!(dst_get_neighbour_noref_raw(&rt->dst)->flags & NTF_ROUTER))) {
-			RT6_TRACE("purging route %p via non-router but gateway\n",
-				  rt);
-			return -1;
+		} else if (rt->rt6i_flags & RTF_GATEWAY) {
+			struct neighbour *neigh;
+			__u8 neigh_flags = 0;
+
+			neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
+			if (neigh) {
+				neigh_flags = neigh->flags;
+				neigh_release(neigh);
+			}
+			if (neigh_flags & NTF_ROUTER) {
+				RT6_TRACE("purging route %p via non-router but gateway\n",
+					  rt);
+				return -1;
+			}
 		}
 		gc_args.more++;
 	}