apps: update to newest macro api

Signed-off-by: Elias Naur <mail@eliasnaur.com>

apps/hello/hello.go

@@ -54,9 +54,10 @@ func loop(w *app.Window) error {
 			cfg = e.Config
 			cs := layout.RigidConstraints(e.Size)
 			ops.Reset()
-			ops.Record()
+			var material ui.MacroOp
+			material.Record(ops)
 			draw.ColorOp{Color: maroon}.Add(ops)
-			material := ops.Stop()
+			material.Stop()
 			text.Label{Material: material, Face: face, Alignment: text.Center, Text: message}.Layout(ops, cs)
 			w.Draw(ops)
 			faces.Frame()