lib: improve cluster/primary code

PR-URL: #53756
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

lib/internal/cluster/primary.js

@@ -221,12 +221,12 @@ function emitForkNT(worker) {
 }
 
 cluster.disconnect = function(cb) {
-  const workers = ObjectKeys(cluster.workers);
+  const workers = ObjectValues(cluster.workers);
 
   if (workers.length === 0) {
     process.nextTick(() => intercom.emit('disconnect'));
   } else {
-    for (const worker of ObjectValues(cluster.workers)) {
+    for (const worker of workers) {
       if (worker.isConnected()) {
         worker.disconnect();
       }
@@ -358,8 +358,6 @@ Worker.prototype.disconnect = function() {
 };
 
 Worker.prototype.destroy = function(signo) {
-  const proc = this.process;
   const signal = signo || 'SIGTERM';
-
-  proc.kill(signal);
+  this.process.kill(signal);
 };