ftrace: remove trace array ctrl

Impact: remove obsolete variable in trace_array structure

With the new start / stop method of ftrace, the ctrl variable
in the trace_array structure is now obsolete. Remove it.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 7b73fd1..be35bdf 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -209,14 +209,12 @@
 static void sched_switch_trace_init(struct trace_array *tr)
 {
 	ctx_trace = tr;
-
-	if (tr->ctrl)
-		start_sched_trace(tr);
+	start_sched_trace(tr);
 }
 
 static void sched_switch_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl && sched_ref)
+	if (sched_ref)
 		stop_sched_trace(tr);
 }