tracing: Add SPDX License format tags to tracing files

Add the SPDX License header to ease license compliance management.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 2e13f77..65a4157a 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1,20 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Kprobes-based tracing events
  *
  * Created by Masami Hiramatsu <mhiramat@redhat.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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 #define pr_fmt(fmt)	"trace_kprobe: " fmt