staging: comedi: ni_pcidio: sample types are unsigned

Sample values in comedi are generally represented as unsigned values.
Change `nidio_interrupt()` to use unsigned types for sample values
(actually bit-vectors of 1-bit sample values) instead of signed types.

Also rename the `AuxData` variable to `auxdata` and change it from
`long` to `unsigned int` as it only needs to hold a 32-bit value.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>