scene: fix compile error in release builds
On release builds, gcc detects a variable uninitialized error, and generates
a warning, which gets converted to an error due to -Werror.
@@ -243,7 +243,7 @@ static void _scene_node_damage_whole(struct wlr_scene_node *node,
lx + child->state.x, ly + child->state.y);
}
- int width, height;
+ int width = 0, height = 0;
switch (node->type) {
case WLR_SCENE_NODE_ROOT:
return;
