[IPV4]: Always set fl.proto in ip_route_newports

ip_route_newports uses the struct flowi from the struct rtable returned
by ip_route_connect for the new route lookup and just replaces the port
numbers if they have changed. If an IPsec policy exists which doesn't match
port 0 the struct flowi won't have the proto field set and no xfrm lookup
is done for the changed ports.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 00f9832..dc0487b 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -119,7 +119,8 @@
 	if (err != 0)
 		goto failure;
 
-	err = ip_route_newports(&rt, inet->sport, inet->dport, sk);
+	err = ip_route_newports(&rt, IPPROTO_DCCP, inet->sport, inet->dport,
+	                        sk);
 	if (err != 0)
 		goto failure;