staging: comedi: ni_tio.h: add identifiers to function parameters

Fix checkpatch.pl warnings of the form "function definition argument
'foo' should also have an identifier name".

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>