drm/omap: dss: Fix refcount leak bugs

In dss_init_ports() and __dss_uninit_ports(), we should call
of_node_put() for the reference returned by of_graph_get_port_by_id()
in fail path or when it is not used anymore.

Fixes: 09bffa6e ("drm: omap: use common OF graph helpers")
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220722144348.1306569-1-windhl@126.com

drivers/gpu/drm/omapdrm/dss/dss.c

@@ -1176,6 +1176,7 @@ static void __dss_uninit_ports(struct dss_device *dss, unsigned int num_ports)
 		default:
 			break;
 		}
+		of_node_put(port);
 	}
 }
 
@@ -1208,11 +1209,13 @@ static int dss_init_ports(struct dss_device *dss)
 		default:
 			break;
 		}
+		of_node_put(port);
 	}
 
 	return 0;
 
 error:
+	of_node_put(port);
 	__dss_uninit_ports(dss, i);
 	return r;
 }