test: fix test-socket-write-after-fin-error

The `'error'` event is not emitted because the socket is already
destroyed when `socket.write()` is called. Use the `socket.write()`
callback instead.

PR-URL: #42340
Refs: #42340 (comment)
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

test/parallel/test-socket-write-after-fin-error.js

@@ -16,18 +16,18 @@ let gotServerError = false;
 
 const server = net.createServer(function(sock) {
   sock.setEncoding('utf8');
-  sock.on('error', function(er) {
-    console.error(`${er.code}: ${er.message}`);
-    gotServerError = er;
-  });
+  sock.on('error', function() {});
 
   sock.on('data', function(c) {
     serverData += c;
   });
   sock.on('end', function() {
     gotServerEnd = true;
     setImmediate(() => {
-      sock.write(serverData);
+      sock.write(serverData, function(er) {
+        console.error(`${er.code}: ${er.message}`);
+        gotServerError = er;
+      });
       sock.end();
     });
   });