hwmon: (nct7802) Add of_node_put() before return

Fix following coccicheck warning:
./drivers/hwmon/nct7802.c:1152:2-24: WARNING: Function
for_each_child_of_node should have of_node_put() before return.

Early exits from for_each_child_of_node should decrement the
node reference counter.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Link: https://lore.kernel.org/r/20211029024918.5161-1-wanjiabing@vivo.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Author: Wan Jiabing

drivers/hwmon/nct7802.c

@@ -1152,8 +1152,10 @@ static int nct7802_configure_channels(struct device *dev,
 		for_each_child_of_node(dev->of_node, node) {
 			err = nct7802_get_channel_config(dev, node, &mode_mask,
 							 &mode_val);
-			if (err)
+			if (err) {
+				of_node_put(node);
 				return err;
+			}
 		}
 	}