staging: comedi: ni_pcidio: (!foo) preferred over (foo == NULL)

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/ni_pcidio.c

@@ -304,7 +304,7 @@ static int ni_pcidio_request_di_mite_channel(struct comedi_device *dev)
 	devpriv->di_mite_chan =
 	    mite_request_channel_in_range(devpriv->mite,
 					  devpriv->di_mite_ring, 1, 2);
-	if (devpriv->di_mite_chan == NULL) {
+	if (!devpriv->di_mite_chan) {
 		spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);
 		dev_err(dev->class_dev, "failed to reserve mite dma channel\n");
 		return -EBUSY;
@@ -924,7 +924,7 @@ static int nidio_auto_attach(struct comedi_device *dev,
 		return ret;
 
 	devpriv->di_mite_ring = mite_alloc_ring(devpriv->mite);
-	if (devpriv->di_mite_ring == NULL)
+	if (!devpriv->di_mite_ring)
 		return -ENOMEM;
 
 	if (board->uses_firmware) {