ipv4: Make output route lookup return rtable directly.

Instead of on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ed9a5b7..95e0c2c 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -922,8 +922,9 @@
 		struct net *net = sock_net(sk);
 
 		security_sk_classify_flow(sk, &fl);
-		err = ip_route_output_flow(net, &rt, &fl, sk);
-		if (err) {
+		rt = ip_route_output_flow(net, &fl, sk);
+		if (IS_ERR(rt)) {
+			err = PTR_ERR(rt);
 			if (err == -ENETUNREACH)
 				IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
 			goto out;