can: hi311x: 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: 57e83fb9 ("can: hi311x: Add Holt HI-311x CAN driver")
Link: https://lore.kernel.org/all/20220719143550.3681-6-mailhol.vincent@wanadoo.frSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/spi/hi311x.c

@@ -667,8 +667,6 @@ static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
 
 			txerr = hi3110_read(spi, HI3110_READ_TEC);
 			rxerr = hi3110_read(spi, HI3110_READ_REC);
-			cf->data[6] = txerr;
-			cf->data[7] = rxerr;
 			tx_state = txerr >= rxerr ? new_state : 0;
 			rx_state = txerr <= rxerr ? new_state : 0;
 			can_change_state(net, cf, tx_state, rx_state);
@@ -681,6 +679,9 @@ static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
 					hi3110_hw_sleep(spi);
 					break;
 				}
+			} else {
+				cf->data[6] = txerr;
+				cf->data[7] = rxerr;
 			}
 		}