wayland: Remove some now-redundant casts

src/video/wayland/SDL_waylandvideo.c

@@ -641,7 +641,7 @@ static void
 Wayland_init_xdg_output(SDL_VideoData *d)
 {
     SDL_WaylandOutputData *node;
-    for (node = (SDL_WaylandOutputData*)d->output_list; node != NULL; node = (SDL_WaylandOutputData*)node->next) {
+    for (node = d->output_list; node != NULL; node = node->next) {
         node->xdg_output = zxdg_output_manager_v1_get_xdg_output(node->videodata->xdg_output_manager, node->output);
         zxdg_output_v1_add_listener(node->xdg_output, &xdg_output_listener, node);
     }