staging: comedi: drivers: ni_mio_cs: 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_mio_cs.c

@@ -163,7 +163,6 @@ static int mio_cs_auto_attach(struct comedi_device *dev,
 {
 	struct pcmcia_device *link = comedi_to_pcmcia_dev(dev);
 	static const struct ni_board_struct *board;
-	struct ni_private *devpriv;
 	int ret;
 
 	board = ni_getboardtype(dev, link);
@@ -188,8 +187,6 @@ static int mio_cs_auto_attach(struct comedi_device *dev,
 	if (ret)
 		return ret;
 
-	devpriv = dev->private;
-
 	return ni_E_init(dev, 0, 1);
 }