Fix NPE message in LLVM.

Change-Id: Ie65060d065d747a6c9ad22c61d5fb29f6cf3c249
diff --git a/src/java_lang_Class.cc b/src/java_lang_Class.cc
index c1d6eb0..2cd7090 100644
--- a/src/java_lang_Class.cc
+++ b/src/java_lang_Class.cc
@@ -426,7 +426,7 @@
 
   NthCallerVisitor visitor(2);
   Thread::Current()->WalkStack(&visitor);
-  Class* caller_class = visitor.declaring_class;
+  Class* caller_class = visitor.caller->GetDeclaringClass();
 
   ClassHelper caller_ch(caller_class);
   if (!caller_class->CanAccess(c)) {