staging: comedi: dt9812: use CR_CHAN() for channel number

As pointed out by Dan Carpenper in
<http://driverdev.linuxdriverproject.org/pipermail/devel/2013-February/036025.html>,
the dt9812 comedi driver's use of the `chanspec` member of `struct
comedi_insn` as a channel number is incorrect.  Change it to use
`CR_CHAN(insn->chanspec)` as the channel number (where `insn` is a
pointer to the `struct comedi_insn` being processed).

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org> # 3.8 onwards
Cc: Anders Blomdell <anders.blomdell@control.lth.se>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/dt9812.c

@@ -947,12 +947,13 @@ static int dt9812_di_rinsn(struct comedi_device *dev,
 			   unsigned int *data)
 {
 	struct comedi_dt9812 *devpriv = dev->private;
+	unsigned int channel = CR_CHAN(insn->chanspec);
 	int n;
 	u8 bits = 0;
 
 	dt9812_digital_in(devpriv->slot, &bits);
 	for (n = 0; n < insn->n; n++)
-		data[n] = ((1 << insn->chanspec) & bits) != 0;
+		data[n] = ((1 << channel) & bits) != 0;
 	return n;
 }
 
@@ -961,12 +962,13 @@ static int dt9812_do_winsn(struct comedi_device *dev,
 			   unsigned int *data)
 {
 	struct comedi_dt9812 *devpriv = dev->private;
+	unsigned int channel = CR_CHAN(insn->chanspec);
 	int n;
 	u8 bits = 0;
 
 	dt9812_digital_out_shadow(devpriv->slot, &bits);
 	for (n = 0; n < insn->n; n++) {
-		u8 mask = 1 << insn->chanspec;
+		u8 mask = 1 << channel;
 
 		bits &= ~mask;
 		if (data[n])
@@ -981,13 +983,13 @@ static int dt9812_ai_rinsn(struct comedi_device *dev,
 			   unsigned int *data)
 {
 	struct comedi_dt9812 *devpriv = dev->private;
+	unsigned int channel = CR_CHAN(insn->chanspec);
 	int n;
 
 	for (n = 0; n < insn->n; n++) {
 		u16 value = 0;
 
-		dt9812_analog_in(devpriv->slot, insn->chanspec, &value,
-				 DT9812_GAIN_1);
+		dt9812_analog_in(devpriv->slot, channel, &value, DT9812_GAIN_1);
 		data[n] = value;
 	}
 	return n;
@@ -998,12 +1000,13 @@ static int dt9812_ao_rinsn(struct comedi_device *dev,
 			   unsigned int *data)
 {
 	struct comedi_dt9812 *devpriv = dev->private;
+	unsigned int channel = CR_CHAN(insn->chanspec);
 	int n;
 	u16 value;
 
 	for (n = 0; n < insn->n; n++) {
 		value = 0;
-		dt9812_analog_out_shadow(devpriv->slot, insn->chanspec, &value);
+		dt9812_analog_out_shadow(devpriv->slot, channel, &value);
 		data[n] = value;
 	}
 	return n;
@@ -1014,10 +1017,11 @@ static int dt9812_ao_winsn(struct comedi_device *dev,
 			   unsigned int *data)
 {
 	struct comedi_dt9812 *devpriv = dev->private;
+	unsigned int channel = CR_CHAN(insn->chanspec);
 	int n;
 
 	for (n = 0; n < insn->n; n++)
-		dt9812_analog_out(devpriv->slot, insn->chanspec, data[n]);
+		dt9812_analog_out(devpriv->slot, channel, data[n]);
 	return n;
 }