net: mv643xx_eth: Drop the NETDEV_TX_BUSY return path

After adding proper stop/wake thresholds, we can expect a queue to never
be full and drop the NETDEV_TX_BUSY return path. In any case, if the queue
cannot accommodate a TSO packet, the packet would be discarded.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mv643xx_eth.c

@@ -996,8 +996,6 @@ static netdev_tx_t mv643xx_eth_xmit(struct sk_buff *skb, struct net_device *dev)
 
 		if (txq->tx_desc_count >= txq->tx_stop_threshold)
 			netif_tx_stop_queue(nq);
-	} else if (ret == -EBUSY) {
-		return NETDEV_TX_BUSY;
 	} else {
 		txq->tx_dropped++;
 		dev_kfree_skb_any(skb);