staging: comedi: ni_670x: cleanup ni_670x_ao_winsn()

For aesthetics, rename this function and tidy it up a bit.
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/ni_670x.c

@@ -86,35 +86,37 @@ struct ni_670x_private {
 	unsigned int ao_readback[32];
 };
 
-static int ni_670x_ao_winsn(struct comedi_device *dev,
+static int ni_670x_ao_insn_write(struct comedi_device *dev,
 				 struct comedi_subdevice *s,
-			    struct comedi_insn *insn, unsigned int *data)
+				 struct comedi_insn *insn,
+				 unsigned int *data)
 {
 	struct ni_670x_private *devpriv = dev->private;
+	unsigned int chan = CR_CHAN(insn->chanspec);
+	unsigned int val = devpriv->ao_readback[chan];
 	int i;
-	int chan = CR_CHAN(insn->chanspec);
-
-	/* Channel number mapping :
-
-	   NI 6703/ NI 6704     | NI 6704 Only
-	   ----------------------------------------------------
-	   vch(0)       :       0       | ich(16)       :       1
-	   vch(1)       :       2       | ich(17)       :       3
-	   .    :       .       |   .                   .
-	   .    :       .       |   .                   .
-	   .    :       .       |   .                   .
-	   vch(15)      :       30      | ich(31)       :       31      */
 
+	/*
+	 * Channel number mapping:
+	 *
+	 * NI 6703/ NI 6704 | NI 6704 Only
+	 * -------------------------------
+	 * vch(0)  :  0     | ich(16) :  1
+	 * vch(1)  :  2     | ich(17) :  3
+	 * ...              | ...
+	 * vch(15) : 30     | ich(31) : 31
+	 */
 	for (i = 0; i < insn->n; i++) {
+		val = data[i];
 		/* First write in channel register which channel to use */
 		writel(((chan & 15) << 1) | ((chan & 16) >> 4),
 		       dev->mmio + AO_CHAN_OFFSET);
 		/* write channel value */
-		writel(data[i], dev->mmio + AO_VALUE_OFFSET);
-		devpriv->ao_readback[chan] = data[i];
+		writel(val, dev->mmio + AO_VALUE_OFFSET);
 	}
+	devpriv->ao_readback[chan] = val;
 
-	return i;
+	return insn->n;
 }
 
 static int ni_670x_ao_rinsn(struct comedi_device *dev,
@@ -241,7 +243,7 @@ static int ni_670x_auto_attach(struct comedi_device *dev,
 	} else {
 		s->range_table = &range_bipolar10;
 	}
-	s->insn_write = &ni_670x_ao_winsn;
+	s->insn_write = ni_670x_ao_insn_write;
 	s->insn_read = &ni_670x_ao_rinsn;
 
 	s = &dev->subdevices[1];