staging: comedi: ni_daq_700: use comedi_pcmcia_disable() for (*detach)

The (*detach) function, daq700_detach() is now a simple wrapper around
comedi_pcmcia_disable(). Just use comedi_pcmcia_disable() directly for
the (*detach).

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>