staging: comedi: adl_pci6208x: use comedi_timeout()

Use comedi_timeout() to wait for the analog output end-of-conversion.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>