[presubmit] Enable readability/namespace linter checking.

src/arm64/simulator-arm64.h

Index: src/arm64/simulator-arm64.h
diff --git a/src/arm64/simulator-arm64.h b/src/arm64/simulator-arm64.h
index e4d9a81ffdbe3d04305726efa911a83a8faaea37..a86a7add666005475791aaabd256d7eec28ec7a1 100644
--- a/src/arm64/simulator-arm64.h
+++ b/src/arm64/simulator-arm64.h
@@ -911,6 +911,7 @@ class SimulatorStack : public v8::internal::AllStatic {
 
 #endif  // !defined(USE_SIMULATOR)
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_ARM64_SIMULATOR_ARM64_H_