simplify list index

Author: Goober5000

code/parse/sexp.cpp

@@ -25208,16 +25208,16 @@ void sexp_set_training_context_fly_path(int node)
 {
 	bool is_nan, is_nan_forever;
 
-	waypoint_list *wp_list = find_matching_waypoint_list(CTEXT(node));
-	if (wp_list == nullptr)
+	int wp_list = find_matching_waypoint_list_index(CTEXT(node));
+	if (wp_list < 0)
 		return;
 
 	int distance = eval_num(CDR(node), is_nan, is_nan_forever);
 	if (is_nan || is_nan_forever)
 		return;
 
 	Training_context |= TRAINING_CONTEXT_FLY_PATH;
-	Training_context_waypoint_path = find_index_of_waypoint_list(wp_list);
+	Training_context_waypoint_path = wp_list;
 	Training_context_distance = static_cast<float>(distance);
 	Training_context_goal_waypoint = 0;
 	Training_context_at_waypoint = -1;

code/scripting/api/libs/mission.cpp

@@ -1486,7 +1486,7 @@ ADE_FUNC(createWaypoint, l_Mission, "[vector Position, waypointlist List]",
 	int waypoint_instance = -1;
 	if (wlh && wlh->isValid())
 	{
-		int wp_list_index = find_index_of_waypoint_list(wlh->getList());
+		int wp_list_index = wlh->wl_index;
 		int wp_index = static_cast<int>(wlh->getList()->get_waypoints().size()) - 1;
 		waypoint_instance = calc_waypoint_instance(wp_list_index, wp_index);
 	}