staging: comedi: mpc8260cpm: 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>
diff --git a/drivers/staging/comedi/drivers/mpc8260cpm.c b/drivers/staging/comedi/drivers/mpc8260cpm.c
index a7fda8f..c0c3329 100644
--- a/drivers/staging/comedi/drivers/mpc8260cpm.c
+++ b/drivers/staging/comedi/drivers/mpc8260cpm.c
@@ -137,7 +137,7 @@
 		return ret;
 
 	for (i = 0; i < 4; i++) {
-		s = dev->subdevices + i;
+		s = &dev->subdevices[i];
 		s->type = COMEDI_SUBD_DIO;
 		s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
 		s->n_chan = 32;