net/mlx4_en: Don't allow aRFS for encapsulated packets

Driver doesn't support aRFS for encapsulated packets, return early error
in such a case.

Fixes: 1eb8c695 ("net/mlx4_en: Add accelerated RFS support")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_netdev.c

@@ -372,6 +372,9 @@ mlx4_en_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 	int nhoff = skb_network_offset(skb);
 	int ret = 0;
 
+	if (skb->encapsulation)
+		return -EPROTONOSUPPORT;
+
 	if (skb->protocol != htons(ETH_P_IP))
 		return -EPROTONOSUPPORT;