[SNDVOL32] Update copyright preamble

This time for `sndvol32.c`.

Author: SigmaTel71

base/applications/sndvol32/sndvol32.c

@@ -1,26 +1,10 @@
 /*
- * ReactOS Sound Volume Control
- * Copyright (C) 2004-2005 Thomas Weidenmueller
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- */
-/*
- * COPYRIGHT:   See COPYING in the top level directory
  * PROJECT:     ReactOS Sound Volume Control
- * FILE:        base/applications/sndvol32/sndvol32.c
- * PROGRAMMERS: Thomas Weidenmueller <w3seek@reactos.com>
+ * LICENSE:     LGPL-2.1-or-later (https://spdx.org/licenses/LGPL-2.1-or-later)
+ * PURPOSE:     Main volume adjustment dialog
+ * COPYRIGHT:   Copyright 2004-2005 Thomas Weidenmueller <w3seek@reactos.com>
+ *              Copyright 2018-2019 Eric Kohl <eric.kohl@reactos.org>
+ *              Copyright 2026 Vitaly Orekhov <vkvo2000@vivaldi.net>
  */
 
 #include "sndvol32.h"