net/mlx4_en: Fix user prio field in XDP forward

The user prio field is wrong (and overflows) in the XDP forward
flow.
This is a result of a bad value for num_tx_rings_p_up, which should
account all XDP TX rings, as they operate for the same user prio.
Signed-off-by: NTariq Toukan <tariqt@mellanox.com>
Reported-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

@@ -1638,7 +1638,8 @@ int mlx4_en_start_port(struct net_device *dev)
 
 	/* Configure tx cq's and rings */
 	for (t = 0 ; t < MLX4_EN_NUM_TX_TYPES; t++) {
-		u8 num_tx_rings_p_up = t == TX ? priv->num_tx_rings_p_up : 1;
+		u8 num_tx_rings_p_up = t == TX ?
+			priv->num_tx_rings_p_up : priv->tx_ring_num[t];
 
 		for (i = 0; i < priv->tx_ring_num[t]; i++) {
 			/* Configure cq */