test: refactor test-enable-in-init

Remove unused function arguments. Convert to ES6 arrow syntax.

PR-URL: #24976
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

Author: Mitch Hankins

test/async-hooks/test-enable-in-init.js

@@ -10,7 +10,7 @@ const nestedHook = async_hooks.createHook({
 let nestedCall = false;
 
 async_hooks.createHook({
-  init: common.mustCall(function(id, type) {
+  init: common.mustCall(() => {
     nestedHook.enable();
     if (!nestedCall) {
       nestedCall = true;