staging: comedi: pcl812: remove 'valid' from private data

This member of the private data is set but never used. Remove it.
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/pcl812.c

@@ -507,8 +507,6 @@ static const struct pcl812_board boardtypes[] = {
 };
 
 struct pcl812_private {
-
-	unsigned char valid;	/*  =1 device is OK */
 	unsigned char dma;	/*  >0 use dma ( usedDMA channel) */
 	unsigned char use_diff;	/*  =1 diff inputs */
 	unsigned char use_MPC;	/*  1=board uses MPC508A multiplexor */
@@ -1497,8 +1495,6 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		break;
 	}
 
-	devpriv->valid = 1;
-
 	pcl812_reset(dev);
 
 	return 0;