net/mlx5e: Add likely to the common RX checksum flow

Most of the packets return true for is_last_ethertype_ip, surround it
with likely compiler hint.
Signed-off-by: Gal Pressman <galp@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en_rx.c

@@ -631,7 +631,7 @@ static inline void mlx5e_handle_csum(struct net_device *netdev,
 		return;
 	}
 
-	if (is_last_ethertype_ip(skb, &network_depth)) {
+	if (likely(is_last_ethertype_ip(skb, &network_depth))) {
 		skb->ip_summed = CHECKSUM_COMPLETE;
 		skb->csum = csum_unfold((__force __sum16)cqe->check_sum);
 		if (network_depth > ETH_HLEN)