staging: comedi: das800: use comedi_handle_events()

cfc_handle_events() is just a wrapper around comedi_handle_events().

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>