expo: Avoid automatically arranging the scene

This should ideally be done once after all scene changes have been made.
Require an explicit call when everything is ready.

Always arrange after a key it sent, just for convenience.

Signed-off-by: Simon Glass <sjg@chromium.org>

boot/bootflow_menu.c

@@ -124,6 +124,10 @@ int bootflow_menu_new(struct expo **expp)
 		priv->num_bootflows++;
 	}
 
+	ret = scene_arrange(scn);
+	if (ret)
+		return log_msg_ret("arr", ret);
+
 	*expp = exp;
 
 	return 0;