staging: comedi: amplc_dio200: remove subdevice pointer math

Convert the comedi_subdevice access from pointer math to array
access.

Use a local variable for the subdevice pointer to keep the line
< 80 chars.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed