smb3: Cleanup license mess

Precise and non-ambiguous license information is important. The recently
added aegis header file has a SPDX license identifier, which is nice, but
at the same time it has a contradictionary license boiler plate text.

  SPDX-License-Identifier: GPL-2.0

versus

  *   This program is free software;  you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
  *   the Free Software Foundation; either version 2 of the License, or
  *   (at your option) any later version.

Oh well.

Assuming that the SPDX identifier is correct and according to x86/hyper-v
contributions from Microsoft GPL V2 only is the usual license.

Remove the boiler plate as it is wrong and even if correct it is redundant.

Fixes: eccb4422 ("smb3: Add ftrace tracepoints for improved SMB3 debugging")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>