staging: comedi: adv_pci1710: use dev->read_subdev

Use the dev->read_subdev that was setup in the device attach instead
of accessing the dev->subdevices array directly.
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>

drivers/staging/comedi/drivers/adv_pci1710.c

@@ -731,7 +731,7 @@ static void interrupt_pci1710_every_sample(void *d)
 {
 	struct comedi_device *dev = d;
 	struct pci1710_private *devpriv = dev->private;
-	struct comedi_subdevice *s = &dev->subdevices[0];
+	struct comedi_subdevice *s = dev->read_subdev;
 	int m;
 #ifdef PCI171x_PARANOIDCHECK
 	const struct boardtype *this_board = comedi_board(dev);
@@ -859,7 +859,7 @@ static void interrupt_pci1710_half_fifo(void *d)
 	struct comedi_device *dev = d;
 	const struct boardtype *this_board = comedi_board(dev);
 	struct pci1710_private *devpriv = dev->private;
-	struct comedi_subdevice *s = &dev->subdevices[0];
+	struct comedi_subdevice *s = dev->read_subdev;
 	int m, samplesinbuf;
 
 	m = inw(dev->iobase + PCI171x_STATUS);