doc: improve async_hooks snippets

PR-URL: #34829
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>

Author: puzpuzpuz

doc/api/async_hooks.md

@@ -273,7 +273,8 @@ async_hooks.createHook({
   init(asyncId, type, triggerAsyncId) {
     const eid = async_hooks.executionAsyncId();
     fs.writeSync(
-      1, `${type}(${asyncId}): trigger: ${triggerAsyncId} execution: ${eid}\n`);
+      process.stdout.fd,
+      `${type}(${asyncId}): trigger: ${triggerAsyncId} execution: ${eid}\n`);
   }
 }).enable();
 
@@ -325,7 +326,7 @@ async_hooks.createHook({
     const eid = async_hooks.executionAsyncId();
     const indentStr = ' '.repeat(indent);
     fs.writeSync(
-      1,
+      process.stdout.fd,
       `${indentStr}${type}(${asyncId}):` +
       ` trigger: ${triggerAsyncId} execution: ${eid}\n`);
   },