can: sun4i_can: sun4i_can_err(): don't count arbitration lose as an error

Losing arbitration is normal in a CAN-bus network, it means that a higher
priority frame is being send and the pending message will be retried later.
Hence most driver only increment arbitration_lost, but the sun4i driver also
incremeants tx_error, causing errors to be reported on a normal functioning
CAN-bus. So stop counting them as errors.

Fixes: 0738eff1 ("can: Allwinner A10/A20 CAN Controller support - Kernel module")
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Link: https://lore.kernel.org/r/20201127095941.21609-1-jhofstee@victronenergy.com
[mkl: split into two seperate patches]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/sun4i_can.c

@@ -604,7 +604,6 @@ static int sun4i_can_err(struct net_device *dev, u8 isrc, u8 status)
 		netdev_dbg(dev, "arbitration lost interrupt\n");
 		alc = readl(priv->base + SUN4I_REG_STA_ADDR);
 		priv->can.can_stats.arbitration_lost++;
-		stats->tx_errors++;
 		if (likely(skb)) {
 			cf->can_id |= CAN_ERR_LOSTARB;
 			cf->data[0] = (alc >> 8) & 0x1f;