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

stable inclusion
from stable-v5.10.137
commit 6ec509679beb2fd6c6616c6958efb58cece0bcf3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6ec509679beb2fd6c6616c6958efb58cece0bcf3

--------------------------------

[ Upstream commit a37b7245 ]

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

Fixes: fd115931 ("can: add Renesas R-Car CAN driver")
Link: https://lore.kernel.org/all/20220719143550.3681-3-mailhol.vincent@wanadoo.fr


Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>