net/mlx4_en: remove napi_hash_del() call

There is no need calling napi_hash_del()+synchronize_rcu() before
calling netif_napi_del()

netif_napi_del() does this already.

Using napi_hash_del() in a driver is useful only when dealing with
a batch of NAPI structures, so that a single synchronize_rcu() can
be used. mlx4_en_deactivate_cq() is deactivating a single NAPI.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

@@ -185,10 +185,6 @@ void mlx4_en_destroy_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq **pcq)
 void mlx4_en_deactivate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq)
 {
 	napi_disable(&cq->napi);
-	if (cq->type == RX) {
-		napi_hash_del(&cq->napi);
-		synchronize_rcu();
-	}
 	netif_napi_del(&cq->napi);
 
 	mlx4_cq_free(priv->mdev->dev, &cq->mcq);