examples: fixup asset example

examples/custom_assets.rs

@@ -5,14 +5,10 @@ fn main() {
 }
 
 fn app(cx: Scope) -> Element {
-    let (disabled, set_disabled) = use_state(&cx, || false);
-
     cx.render(rsx! {
         div {
-            "hi"
+            "This should show an image:"
-            img {
+            img { src: "examples/assets/logo.png", }
-                src: "examples/../../../assets/logo.png",
-            }
         }
     })
 }