gpu: ipu-v3: prg: fix device node leak in ipu_prg_lookup_by_phandle

Before returning, call of_node_put() for the device node returned by
of_parse_phandle().

Fixes: ea9c260514c1 ("gpu: ipu-v3: add driver for Prefetch Resolve Gasket")
Signed-off-by: Tobias Jordan <Tobias.Jordan@elektrobit.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/gpu/ipu-v3/ipu-prg.c b/drivers/gpu/ipu-v3/ipu-prg.c
index 067365c..97b9950 100644
--- a/drivers/gpu/ipu-v3/ipu-prg.c
+++ b/drivers/gpu/ipu-v3/ipu-prg.c
@@ -102,11 +102,14 @@ ipu_prg_lookup_by_phandle(struct device *dev, const char *name, int ipu_id)
 			mutex_unlock(&ipu_prg_list_mutex);
 			device_link_add(dev, prg->dev, DL_FLAG_AUTOREMOVE);
 			prg->id = ipu_id;
+			of_node_put(prg_node);
 			return prg;
 		}
 	}
 	mutex_unlock(&ipu_prg_list_mutex);
 
+	of_node_put(prg_node);
+
 	return NULL;
 }