staging: comedi: hwrdv_apci3120: 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/addi-data/hwdrv_apci3120.c

@@ -1414,7 +1414,7 @@ static void v_APCI3120_InterruptDma(int irq, void *d)
 {
 	struct comedi_device *dev = d;
 	struct addi_private *devpriv = dev->private;
-	struct comedi_subdevice *s = &dev->subdevices[0];
+	struct comedi_subdevice *s = dev->read_subdev;
 	unsigned int next_dma_buf, samplesinbuf;
 	unsigned long low_word, high_word, var;
 	unsigned int ui_Tmp;
@@ -1568,8 +1568,8 @@ static void v_APCI3120_InterruptDma(int irq, void *d)
 static int i_APCI3120_InterruptHandleEos(struct comedi_device *dev)
 {
 	struct addi_private *devpriv = dev->private;
+	struct comedi_subdevice *s = dev->read_subdev;
 	int n_chan, i;
-	struct comedi_subdevice *s = &dev->subdevices[0];
 	int err = 1;
 
 	n_chan = devpriv->ui_AiNbrofChannels;
@@ -1593,11 +1593,11 @@ static void v_APCI3120_Interrupt(int irq, void *d)
 {
 	struct comedi_device *dev = d;
 	struct addi_private *devpriv = dev->private;
+	struct comedi_subdevice *s = dev->read_subdev;
 	unsigned short int_daq;
 	unsigned int int_amcc, ui_Check, i;
 	unsigned short us_TmpValue;
 	unsigned char b_DummyRead;
-	struct comedi_subdevice *s = &dev->subdevices[0];
 
 	ui_Check = 1;