ART: Move to using locks.h instead of mutex.h

When only annotating lock requirements, use locks.h.

Bug: 119869270
Test: mmma art
Change-Id: I1608b03254712feff0072ebad012c3af0cc3dda4
diff --git a/runtime/monitor_objects_stack_visitor.h b/runtime/monitor_objects_stack_visitor.h
index c943402..3968239 100644
--- a/runtime/monitor_objects_stack_visitor.h
+++ b/runtime/monitor_objects_stack_visitor.h
@@ -20,7 +20,7 @@
 #include <android-base/logging.h>
 
 #include "art_method.h"
-#include "base/mutex.h"
+#include "base/locks.h"
 #include "monitor.h"
 #include "stack.h"
 #include "thread.h"