bnxt: count Tx drops

Drivers should count packets they are dropping.

Fixes: c0c050c5 ("bnxt_en: New Broadcom ethernet driver.")
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -412,6 +412,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	i = skb_get_queue_mapping(skb);
 	if (unlikely(i >= bp->tx_nr_rings)) {
 		dev_kfree_skb_any(skb);
+		atomic_long_inc(&dev->tx_dropped);
 		return NETDEV_TX_OK;
 	}
 
@@ -687,6 +688,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (txr->kick_pending)
 		bnxt_txr_db_kick(bp, txr, txr->tx_prod);
 	txr->tx_buf_ring[txr->tx_prod].skb = NULL;
+	atomic_long_inc(&dev->tx_dropped);
 	return NETDEV_TX_OK;
 }