staging: comedi: addi_apci_3120: remove 'check' param from apci3120_setup_chan_list()

This parameter is always passed as '0'. Remove it and refactor the code.

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>