mlx4: do not call napi_schedule() without care

Disable BH around the call to napi_schedule() to avoid following warning

[   52.095499] NOHZ: local_softirq_pending 08
[   52.421291] NOHZ: local_softirq_pending 08
[   52.608313] NOHZ: local_softirq_pending 08

Fixes: 8d59de8 ("net/mlx4_en: Process all completions in RX rings after port goes up")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Erez Shitrit <erezsh@mellanox.com>
Cc: Eugenia Emantayev <eugenia@mellanox.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: edumazet

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

@@ -1748,8 +1748,11 @@ int mlx4_en_start_port(struct net_device *dev)
 	/* Process all completions if exist to prevent
 	 * the queues freezing if they are full
 	 */
-	for (i = 0; i < priv->rx_ring_num; i++)
+	for (i = 0; i < priv->rx_ring_num; i++) {
+		local_bh_disable();
 		napi_schedule(&priv->rx_cq[i]->napi);
+		local_bh_enable();
+	}
 
 	netif_tx_start_all_queues(dev);
 	netif_device_attach(dev);