staging: comedi: adl_pci9118: cleanup and simplify pci9118_reset()

Change the return type to void, this function always succeeds and the
callers never check the return value.

According to the The User Manual for the PCI-9118, the hardware does not
require any particular "reset" in order to function. Simplify the reset
so it justs gets the board info a known state with interrupts disabled.

There is no reason to initialize the private data members in this function.
They all default to '0' due to the kzalloc() of the private data and the
subdevice operations all initialize them as needed.

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>