On Sun, Mar 26, 2023 at 05:42:17AM +0000, Wei Chen wrote:

If there is a failure during copy_from_user or user-provided data buffer is
invalid, rtl_debugfs_set_write_reg should return negative error code instead
of a positive value count.

Fix this bug by returning correct error code. Moreover, the check of buffer
against null is removed since it will be handled by copy_from_user.

Fixes: 610247f46feb ("rtlwifi: Improve debugging by using debugfs")
Signed-off-by: Wei Chen <redacted>

Reviewed-by: Simon Horman <redacted>