treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 465

Based on 1 normalized pattern(s):

  released under the gpl version 2 only

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081202.506564860@linutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

samples/kfifo/bytestream-example.c

+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Sample kfifo byte stream implementation
  *
  * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net>
- *
- * Released under the GPL version 2 only.
- *
  */
 
 #include <linux/init.h>

samples/kfifo/dma-example.c

+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Sample fifo dma implementation
  *
  * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net>
- *
- * Released under the GPL version 2 only.
- *
  */
 
 #include <linux/init.h>

samples/kfifo/inttype-example.c

+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Sample kfifo int type implementation
  *
  * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net>
- *
- * Released under the GPL version 2 only.
- *
  */
 
 #include <linux/init.h>

samples/kfifo/record-example.c

+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Sample dynamic sized record fifo implementation
  *
  * Copyright (C) 2010 Stefani Seibold <stefani@seibold.net>
- *
- * Released under the GPL version 2 only.
- *
  */
 
 #include <linux/init.h>