remove the builder from the controller sample

@@ -50,9 +50,7 @@ class _BarcodeScannerWithControllerState
     return Scaffold(
       appBar: AppBar(title: const Text('With controller')),
       backgroundColor: Colors.black,
-      body: Builder(
-        builder: (context) {
-          return Stack(
+      body: Stack(
         children: [
           MobileScanner(
             controller: controller,
@@ -78,8 +76,7 @@ class _BarcodeScannerWithControllerState
                       height: 50,
                       child: FittedBox(
                         child: Text(
-                              barcode?.barcodes.first.rawValue ??
-                                  'Scan something!',
+                          barcode?.barcodes.first.rawValue ?? 'Scan something!',
                           overflow: TextOverflow.fade,
                           style: Theme.of(context)
                               .textTheme
@@ -96,8 +93,6 @@ class _BarcodeScannerWithControllerState
             ),
           ),
         ],
-          );
-        },
       ),
     );
   }