tracing: Update instance_rmdir() to use tracefs_remove_recursive

Update instancd_rmdir to use tracefs_remove_recursive instead of
debugfs_remove_recursive.This was left in the transition from debugfs
to tracefs.

Link: http://lkml.kernel.org/r/1445169490-18315-2-git-send-email-hello.wjx@gmail.com

Cc: stable@vger.kernel.org # 4.1+
Fixes: 8434dc9340 ("tracing: Convert the tracing facility over to use tracefs")
Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -6689,7 +6689,7 @@ static int instance_rmdir(const char *name)
 	tracing_set_nop(tr);
 	event_trace_del_tracer(tr);
 	ftrace_destroy_function_files(tr);
-	debugfs_remove_recursive(tr->dir);
+	tracefs_remove_recursive(tr->dir);
 	free_trace_buffers(tr);
 
 	for (i = 0; i < tr->nr_topts; i++) {