leds: trigger: netdev: refactor code setting device name

Move the code into a helper, ready for it to be called at
other times. No intended behaviour change.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/leds/trigger/ledtrig-netdev.c

@@ -104,15 +104,9 @@ static ssize_t device_name_show(struct device *dev,
 	return len;
 }
 
-static ssize_t device_name_store(struct device *dev,
-				 struct device_attribute *attr, const char *buf,
-				 size_t size)
+static int set_device_name(struct led_netdev_data *trigger_data,
+			   const char *name, size_t size)
 {
-	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
-
-	if (size >= IFNAMSIZ)
-		return -EINVAL;
-
 	cancel_delayed_work_sync(&trigger_data->work);
 
 	mutex_lock(&trigger_data->lock);
@@ -122,7 +116,7 @@ static ssize_t device_name_store(struct device *dev,
 		trigger_data->net_dev = NULL;
 	}
 
-	memcpy(trigger_data->device_name, buf, size);
+	memcpy(trigger_data->device_name, name, size);
 	trigger_data->device_name[size] = 0;
 	if (size > 0 && trigger_data->device_name[size - 1] == '\n')
 		trigger_data->device_name[size - 1] = 0;
@@ -140,6 +134,23 @@ static ssize_t device_name_store(struct device *dev,
 	set_baseline_state(trigger_data);
 	mutex_unlock(&trigger_data->lock);
 
+	return 0;
+}
+
+static ssize_t device_name_store(struct device *dev,
+				 struct device_attribute *attr, const char *buf,
+				 size_t size)
+{
+	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
+	int ret;
+
+	if (size >= IFNAMSIZ)
+		return -EINVAL;
+
+	ret = set_device_name(trigger_data, buf, size);
+
+	if (ret < 0)
+		return ret;
 	return size;
 }