staging: comedi: amplc_pci230: tidy up stuct pci230_private

Align the member comments a bit better in the declaration of `struct
pci230_private`.  Also remove the heading comment as it is just a
boilerplate comedi comment.

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>