remove hooks from objects

Remove the hooks we installed on objects in the destroy/free event
or before calling _destroy. This is not really needed but it is
a nice thing to do because it calls the hook removed callbacks.

src/modules/module-metadata/metadata.c

@@ -123,6 +123,8 @@ static void global_unbind(void *data)
 {
 	struct resource_data *d = data;
 	if (d->resource) {
+	        spa_hook_remove(&d->resource_listener);
+	        spa_hook_remove(&d->object_listener);
 	        spa_hook_remove(&d->metadata_listener);
 	        spa_hook_remove(&d->impl_resource_listener);
 	}