arc: kernel: Return -EFAULT if copy_to_user() fails

stable inclusion
from stable-5.10.32
commit b448a6a2fc5aa7c36403ebfb2dcbf767d3b01eb4
bugzilla: 51796

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

[ Upstream commit 46e15218 ]

The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return -EFAULT if the copy doesn't complete.

Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>