staging: comedi: cb_das16_cs: rename private data member 'status[12]'

For aesthetics, rename these private data members to match the registers
they are associated with.

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>