tracing: Rename trace_event_mutex to trace_event_sem

trace_event_mutex is an rw semaphore now, not a mutex, change the name.

Link: http://lkml.kernel.org/r/513D843B.40109@huawei.com

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
[ Forward ported to my new code ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index af77870..127a9d8 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -33,7 +33,7 @@
 
 /* used by module unregistering */
 extern int __unregister_ftrace_event(struct trace_event *event);
-extern struct rw_semaphore trace_event_mutex;
+extern struct rw_semaphore trace_event_sem;
 
 #define MAX_MEMHEX_BYTES	8
 #define HEX_CHARS		(MAX_MEMHEX_BYTES*2 + 1)