make container_finish private

include/sway/tree/container.h

@@ -130,9 +130,6 @@ struct sway_container *container_view_create(
 // TODO don't return the parent on destroy
 struct sway_container *container_destroy(struct sway_container *container);
 
-// TODO make me private
-struct sway_container *container_finish(struct sway_container *cont);
-
 struct sway_container *container_close(struct sway_container *container);
 
 // TODO move to layout.c

sway/tree/container.c

@@ -77,7 +77,7 @@ struct sway_container *container_create(enum sway_container_type type) {
 	return c;
 }
 
-struct sway_container *container_finish(struct sway_container *cont) {
+static struct sway_container *container_finish(struct sway_container *cont) {
 	if (cont == NULL) {
 		return NULL;
 	}