Disambiguate expressions in rsx by requiring curlies

examples/control_focus.rs

@@ -16,7 +16,7 @@ fn app(cx: Scope) -> Element {
             loop {
                 tokio::time::sleep(std::time::Duration::from_millis(10)).await;
                 if let Some(element) = elements.read().get(focused) {
-                    element.set_focus(true);
+                    _ = element.set_focus(true).await;
                 } else {
                     focused = 0;
                 }