staging: comedi: adv_pci1723: checkpatch.pl cleanup (missing blank line)

Fix this checkpatch.pl warning:

WARNING: Missing a blank line after declarations
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/adv_pci1723.c

@@ -161,11 +161,10 @@ static int pci1723_ao_write_winsn(struct comedi_device *dev,
 				  struct comedi_insn *insn, unsigned int *data)
 {
 	struct pci1723_private *devpriv = dev->private;
-	int n, chan;
-	chan = CR_CHAN(insn->chanspec);
+	unsigned int chan = CR_CHAN(insn->chanspec);
+	int n;
 
 	for (n = 0; n < insn->n; n++) {
-
 		devpriv->ao_data[chan] = data[n];
 		outw(data[n], dev->iobase + PCI1723_DA(chan));
 	}