Just visit classes_root, not its elements

Change-Id: Ide0de6fda31de47b9c7fe2e33698b7f10ef44707
diff --git a/src/class_linker.h b/src/class_linker.h
index 6323fb7..d6c2f0c 100644
--- a/src/class_linker.h
+++ b/src/class_linker.h
@@ -47,7 +47,7 @@
 
   // TODO replace with heap interface
   typedef void (RootVistor)(Object* root, void* arg);
-  void VisitRoots(RootVistor* rootVisitor, void* arg);
+  void VisitRoots(RootVistor* root_visitor, void* arg);
 
  private:
   ClassLinker() {}