The comedi core expects the (*attach) functions to return < 0 to indicate
an error or >= 0 for success. Change the return to '0' as that is more
typical.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Reviewed-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>