staging: comedi: adl_pci9118: rename setup_channel_list()

Rename this function so it has namespace associated with the driver.

Also, this function always succeeds. Change the return type to void
and remove the unnecessary error handling by the callers.

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>