treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 403

Based on 1 normalized pattern(s):

  this software may be redistributed and or modified under the terms
  of the gnu general public license gpl version 2 as published by the
  free software foundation

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 1 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190112.039124428@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mm/dmapool.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * DMA Pool allocator
  *
@@ -5,10 +6,6 @@
  * Copyright 2007 Intel Corporation
  *   Author: Matthew Wilcox <willy@linux.intel.com>
  *
- * This software may be redistributed and/or modified under the terms of
- * the GNU General Public License ("GPL") version 2 as published by the
- * Free Software Foundation.
- *
  * This allocator returns small blocks of a given size which are DMA-able by
  * the given device.  It uses the dma_alloc_coherent page allocator to get
  * new pages, then splits them up into blocks of the required size.