net/mlx4_en: Remove unnecessary checks when setting num channels

Boundaries checks for the number of RX, TX, other and combined channels
should be checked by the caller and not in the driver.

In addition, remove wrong memset on get channels as it overrides the cmd
field in the requester struct.
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: NTariq Toukan <tariqt@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

@@ -1732,8 +1732,6 @@ static void mlx4_en_get_channels(struct net_device *dev,
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
 
-	memset(channel, 0, sizeof(*channel));
-
 	channel->max_rx = MAX_RX_RINGS;
 	channel->max_tx = MLX4_EN_MAX_TX_RING_P_UP;
 
@@ -1752,10 +1750,7 @@ static int mlx4_en_set_channels(struct net_device *dev,
 	int xdp_count;
 	int err = 0;
 
-	if (channel->other_count || channel->combined_count ||
-	    channel->tx_count > MLX4_EN_MAX_TX_RING_P_UP ||
-	    channel->rx_count > MAX_RX_RINGS ||
-	    !channel->tx_count || !channel->rx_count)
+	if (!channel->tx_count || !channel->rx_count)
 		return -EINVAL;
 
 	tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);