mpls: Fix allowed protocols for mpls gso

MPLS and Tunnel GSO does not work together.  Reject packet which
request such GSO.

Fixes: 0d89d203 ("MPLS: Add limited GSO support").
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mpls/mpls_gso.c

@@ -31,10 +31,7 @@ static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
 				  SKB_GSO_TCPV6 |
 				  SKB_GSO_UDP |
 				  SKB_GSO_DODGY |
-				  SKB_GSO_TCP_ECN |
-				  SKB_GSO_GRE |
-				  SKB_GSO_GRE_CSUM |
-				  SKB_GSO_IPIP)))
+				  SKB_GSO_TCP_ECN)))
 		goto out;
 
 	/* Setup inner SKB. */