ftrace: start wakeup tracing after setting function tracer

Enabling the wakeup tracer before enabling the function tracing causes
some strange results due to the dynamic enabling of the functions.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/trace/trace_sched_wakeup.c

@@ -352,9 +352,10 @@ static void start_wakeup_tracer(struct trace_array *tr)
 	 */
 	smp_wmb();
 
-	tracer_enabled = 1;
 	register_ftrace_function(&trace_ops);
 
+	tracer_enabled = 1;
+
 	return;
 fail_deprobe_wake_new:
 	marker_probe_unregister("kernel_sched_wakeup_new",