backlight: sky81452-backlight: Fix refcount imbalance on error

When of_property_read_u32_array() returns an error code, a
pairing refcount decrement is needed to keep np's refcount
balanced.

Fixes: f705806c ("backlight: Add support Skyworks SKY81452 backlight driver")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/video/backlight/sky81452-backlight.c

@@ -217,6 +217,7 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
 					num_entry);
 		if (ret < 0) {
 			dev_err(dev, "led-sources node is invalid.\n");
+			of_node_put(np);
 			return ERR_PTR(-EINVAL);
 		}