vfio-pci/zdev: Remove repeated verbose license text

The SPDX and verbose license text are redundant, however in this case
the verbose license indicates a GPL v2 only while SPDX specifies v2+.
Remove the verbose license and correct SPDX to the more restricted
version.

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20210824003749.1039-1-caihuoqing@baidu.com
[aw: commit log]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Author: caihuoqing1990

drivers/vfio/pci/vfio_pci_zdev.c

@@ -1,15 +1,10 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * VFIO ZPCI devices support
  *
  * Copyright (C) IBM Corp. 2020.  All rights reserved.
  *	Author(s): Pierre Morel <pmorel@linux.ibm.com>
  *                 Matthew Rosato <mjrosato@linux.ibm.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  */
 #include <linux/io.h>
 #include <linux/pci.h>