ART: Refactor for bugprone-argument-comment

Handles runtime.

Bug: 116054210
Test: WITH_TIDY=1 mmma art
Change-Id: Ibc0d5086809d647f0ce4df5452eb84442d27ecf0
diff --git a/runtime/class_loader_utils.h b/runtime/class_loader_utils.h
index 78ad568..945d659 100644
--- a/runtime/class_loader_utils.h
+++ b/runtime/class_loader_utils.h
@@ -160,7 +160,7 @@
   VisitClassLoaderDexFiles<decltype(helper), void*>(soa,
                                                     class_loader,
                                                     helper,
-                                                    /* default */ nullptr);
+                                                    /* default= */ nullptr);
 }
 
 }  // namespace art