test: improve test-vm-context-async-script

Author: jasnell

test/parallel/test-vm-context-async-script.js

@@ -20,16 +20,16 @@
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 'use strict';
-require('../common');
+const common = require('../common');
 const assert = require('assert');
 const vm = require('vm');
 
-const sandbox = { setTimeout: setTimeout };
+const sandbox = { setTimeout };
 
 const ctx = vm.createContext(sandbox);
 
 vm.runInContext('setTimeout(function() { x = 3; }, 0);', ctx);
-setTimeout(function() {
+setTimeout(common.mustCall(() => {
   assert.strictEqual(sandbox.x, 3);
   assert.strictEqual(ctx.x, 3);
-}, 1);
+}), 1);