staging: comedi: aio_iiro_16: remove subdevice pointer math

Convert the comedi_subdevice access from pointer math to array
access.

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

drivers/staging/comedi/drivers/aio_iiro_16.c

@@ -112,15 +112,15 @@ static int aio_iiro_16_attach(struct comedi_device *dev,
 	if (ret)
 		return ret;
 
-	s = dev->subdevices + 0;
+	s = &dev->subdevices[0];
 	s->type = COMEDI_SUBD_DIO;
 	s->subdev_flags = SDF_WRITABLE;
 	s->n_chan = 16;
 	s->maxdata = 1;
 	s->range_table = &range_digital;
 	s->insn_bits = aio_iiro_16_dio_insn_bits_write;
 
-	s = dev->subdevices + 1;
+	s = &dev->subdevices[1];
 	s->type = COMEDI_SUBD_DIO;
 	s->subdev_flags = SDF_READABLE;
 	s->n_chan = 16;