staging: comedi: Use '"%s:", __func__' instead of function name

Replace an occurrence of the function name in a string by a reference
to __func__, to improve robustness. Problem found with checkpatch.
Signed-off-by: NEisha Chen-yen-su <chenyensu0@gmail.com>
Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/s626.c

@@ -1700,7 +1700,7 @@ static int s626_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 
 	if (devpriv->ai_cmd_running) {
 		dev_err(dev->class_dev,
-			"s626_ai_cmd: Another ai_cmd is running\n");
+			"%s: Another ai_cmd is running\n", __func__);
 		return -EBUSY;
 	}
 	/* disable interrupt */