can: sun4i_can: do not report txerr and rxerr during bus-off

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: 0738eff1 ("can: Allwinner A10/A20 CAN Controller support - Kernel module")
Link: https://lore.kernel.org/all/20220719143550.3681-7-mailhol.vincent@wanadoo.fr
CC: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/sun4i_can.c

@@ -535,11 +535,6 @@ static int sun4i_can_err(struct net_device *dev, u8 isrc, u8 status)
 	rxerr = (errc >> 16) & 0xFF;
 	txerr = errc & 0xFF;
 
-	if (skb) {
-		cf->data[6] = txerr;
-		cf->data[7] = rxerr;
-	}
-
 	if (isrc & SUN4I_INT_DATA_OR) {
 		/* data overrun interrupt */
 		netdev_dbg(dev, "data overrun interrupt\n");
@@ -570,6 +565,10 @@ static int sun4i_can_err(struct net_device *dev, u8 isrc, u8 status)
 		else
 			state = CAN_STATE_ERROR_ACTIVE;
 	}
+	if (skb && state != CAN_STATE_BUS_OFF) {
+		cf->data[6] = txerr;
+		cf->data[7] = rxerr;
+	}
 	if (isrc & SUN4I_INT_BUS_ERR) {
 		/* bus error interrupt */
 		netdev_dbg(dev, "bus error interrupt\n");