Staging: comedi: fix printk issue in ni_labpc_cs.c

This is a patch to the ni_labpc_cs.c file that fixes up a printk
warning found by the checkpatch.pl tool
Signed-off-by: NRavishankar Karkala Mallikarjunayya <ravishankar.km@greenturtles.in>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/comedi/drivers/ni_labpc_cs.c

@@ -145,7 +145,7 @@ static int labpc_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		irq = link->irq;
 		break;
 	default:
-		printk("bug! couldn't determine board type\n");
+		pr_err("bug! couldn't determine board type\n");
 		return -EINVAL;
 		break;
 	}