Fixed command-line launch segfault

custom_menu_destroy() was causing a segfault when launching the game via
command-line parameters

src/menu/custom_menu.c

@@ -295,7 +295,6 @@ void custom_menu_loop(void) {
     if (sGotoGame) {
         sSelectedFileNum = sGotoGame;
         custom_menu_close_system();
-        custom_menu_destroy();
     }
 
     // force-start the load when command-line server hosting

src/menu/custom_menu_system.c

@@ -97,9 +97,6 @@ void custom_menu_system_init(void) {
 
 void custom_menu_destroy(void) {
     //  TODO: clean up all of the calloc()'d memory
-    sHead = NULL;
-    sCurrentMenu = NULL;
-    sLastMenu = NULL;
 }
 
 void custom_menu_system_loop(void) {