i8k: Return -ENODATA for invalid temperature

Guenter Roeck suggested to return -ENODATA instead -ERANGE or -EINVAL when BIOS
reports invalid temperature value.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>