[presubmit] Enable readability/namespace linter checking.

src/transitions-inl.h

Index: src/transitions-inl.h
diff --git a/src/transitions-inl.h b/src/transitions-inl.h
index f31eff96ba19e6e8e1dca0f1a4b3ee0c7c654a53..a5ec52f66730a131a8e5e3a58ecda049f77c9b0c 100644
--- a/src/transitions-inl.h
+++ b/src/transitions-inl.h
@@ -173,6 +173,7 @@ void TransitionArray::SetNumberOfTransitions(int number_of_transitions) {
   set(kTransitionLengthIndex, Smi::FromInt(number_of_transitions));
 }
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_TRANSITIONS_INL_H_