test: show incorrect value on test failure

PR-URL: #16818
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Gireesh Punathil <[email protected]>
Reviewed-By: Rich Trott <[email protected]>
Reviewed-By: Khaidi Chu <[email protected]>

Author: Sean Karson

test/async-hooks/test-promise.promise-before-init-hooks.js

@@ -16,7 +16,7 @@ hooks.enable();
 p.then(function afterresolution(val) {
   assert.strictEqual(val, 5);
   const as = hooks.activitiesOfTypes('PROMISE');
-  assert.strictEqual(as.length, 1, 'one activity');
+  assert.strictEqual(as.length, 1);
   checkInvocations(as[0], { init: 1, before: 1 },
                    'after resolution child promise');
   return val;