net: dsa: tag_qca: fix doubled Tx statistics

[ Upstream commit bd5874da ]

DSA subsystem takes care of netdev statistics since commit 4ed70ce9
("net: dsa: Refactor transmit path to eliminate duplication"), so
any accounting inside tagger callbacks is redundant and can lead to
messing up the stats.
This bug is present in Qualcomm tagger since day 0.

Fixes: cafdc45c ("net-next: dsa: add Qualcomm tag RX/TX handler")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Alexander Lobakin <alobakin@dlink.ru>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/dsa/tag_qca.c

@@ -41,9 +41,6 @@ static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct dsa_port *dp = dsa_slave_to_port(dev);
 	u16 *phdr, hdr;
 
-	dev->stats.tx_packets++;
-	dev->stats.tx_bytes += skb->len;
-
 	if (skb_cow_head(skb, 0) < 0)
 		return NULL;