staging: comedi: drivers: ni_atmio: Removed variables that is never used

Variable ar assigned a value that is never used.
I have also removed all the code that thereby serves no purpose.

This was found using a static code analysis program called cppcheck
Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_atmio.c

@@ -300,7 +300,6 @@ static int ni_atmio_attach(struct comedi_device *dev,
 			   struct comedi_devconfig *it)
 {
 	const struct ni_board_struct *boardtype;
-	struct ni_private *devpriv;
 	struct pnp_dev *isapnp_dev;
 	int ret;
 	unsigned long iobase;
@@ -310,7 +309,6 @@ static int ni_atmio_attach(struct comedi_device *dev,
 	ret = ni_alloc_private(dev);
 	if (ret)
 		return ret;
-	devpriv = dev->private;
 
 	iobase = it->options[0];
 	irq = it->options[1];