staging: comedi: pcl816: reduce indent level in pcl816_ai_cancel()

If an async command is not running the (*cancel) function doesn't do
anything. Exit the function early if this is the case.

This allows reducing the indent level in the rest of the function.
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/pcl816.c

@@ -549,7 +549,9 @@ static int pcl816_ai_cancel(struct comedi_device *dev,
 {
 	struct pcl816_private *devpriv = dev->private;
 
-	if (devpriv->ai_cmd_running) {
+	if (!devpriv->ai_cmd_running)
+		return 0;
+
 	switch (devpriv->int816_mode) {
 	case INT_TYPE_AI1_DMA:
 	case INT_TYPE_AI3_DMA:
@@ -576,10 +578,9 @@ static int pcl816_ai_cancel(struct comedi_device *dev,
 		devpriv->ai_cmd_running = 0;
 		devpriv->irq_was_now_closed = 1;
 		devpriv->int816_mode = 0;
-/* s->busy = 0; */
 		break;
 	}
-	}
+
 	return 0;
 }