staging: comedi: aio_aio12_8: replace comedi_board() calls

The `comedi_board(dev)` inline function calls just return
`dev->board_ptr`.  Expand the inline function calls.
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>

drivers/staging/comedi/drivers/aio_aio12_8.c

@@ -178,7 +178,7 @@ static const struct comedi_lrange range_aio_aio12_8 = {
 static int aio_aio12_8_attach(struct comedi_device *dev,
 			      struct comedi_devconfig *it)
 {
-	const struct aio12_8_boardtype *board = comedi_board(dev);
+	const struct aio12_8_boardtype *board = dev->board_ptr;
 	struct comedi_subdevice *s;
 	int ret;