There seems to be some confusion here which functions return positive
numbers and which return negative error codes.

copy_to_user() returns the number of bytes remaining to be copied but we
want to return -EFAULT.

The rest is just clean up.  get_user() actually returns zero on success
and -EFAULT on error so we can preserve the error code.  The
timeout_to_regval() function returns -EINVAL on failure, but we can
propogate that back instead of hardcoding -EINVAL ourselves.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
--