trace: Call tracing_reset_online_cpus before tracer->init()

Impact: cleanup

To make it easy for ftrace plugin writers, as this was open coded in
the existing plugins

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Frédéric Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index eaca5ad..84ca9d8 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -226,15 +226,6 @@
 		stop_stack_timer(cpu);
 }
 
-static void start_stack_trace(struct trace_array *tr)
-{
-	mutex_lock(&sample_timer_lock);
-	tracing_reset_online_cpus(tr);
-	start_stack_timers();
-	tracer_enabled = 1;
-	mutex_unlock(&sample_timer_lock);
-}
-
 static void stop_stack_trace(struct trace_array *tr)
 {
 	mutex_lock(&sample_timer_lock);
@@ -247,7 +238,10 @@
 {
 	sysprof_trace = tr;
 
-	start_stack_trace(tr);
+	mutex_lock(&sample_timer_lock);
+	start_stack_timers();
+	tracer_enabled = 1;
+	mutex_unlock(&sample_timer_lock);
 	return 0;
 }