gobj: don't create pointless future in TextureReloadRequest

panda/src/gobj/textureReloadRequest.cxx

@@ -40,7 +40,7 @@ do_task() {
       // become a kind of a leak (if the texture is never rendered again on
       // this GSG, we'll just end up carrying the texture memory in RAM
       // forever, instead of dumping it as soon as it gets prepared).
-      _texture->prepare(_pgo);
+      _pgo->enqueue_texture(_texture);
     }
   }