kernel: cgroup: Add SPDX-License-Identifier lines

Add GPL-2.0 SPDX license id lines to a few old
files, replacing the reference to the COPYING file.

The COPYING file at the time of creation of these files
(2007 and 2005) was GPL-v2.0, with an additional clause
indicating that only v2 applied.

Signed-off-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Author: tbird20d

kernel/cgroup/cgroup.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  Generic process-grouping system.
  *
@@ -20,10 +21,6 @@
  *  2003-10-22 Updates by Stephen Hemminger.
  *  2004 May-July Rework by Paul Jackson.
  *  ---------------------------------------------------
- *
- *  This file is subject to the terms and conditions of the GNU General Public
- *  License.  See the file COPYING in the main directory of the Linux
- *  distribution for more details.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

kernel/cgroup/cpuset.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  kernel/cpuset.c
  *
@@ -16,10 +17,6 @@
  *  2006 Rework by Paul Menage to use generic cgroups
  *  2008 Rework of the scheduler domains and CPU hotplug handling
  *       by Max Krasnyansky
- *
- *  This file is subject to the terms and conditions of the GNU General Public
- *  License.  See the file COPYING in the main directory of the Linux
- *  distribution for more details.
  */
 #include "cpuset-internal.h"