[presubmit] Enable readability/namespace linter checking.

src/arm/interface-descriptors-arm.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_ARM_INTERFACE_DESCRIPTORS_ARM_H_
 #define V8_ARM_INTERFACE_DESCRIPTORS_ARM_H_
 
 #include "src/interface-descriptors.h"
 
 namespace v8 {
 namespace internal {
 
 class PlatformInterfaceDescriptor {
  public:
   explicit PlatformInterfaceDescriptor(TargetAddressStorageMode storage_mode)
       : storage_mode_(storage_mode) {}
 
   TargetAddressStorageMode storage_mode() { return storage_mode_; }
 
  private:
   TargetAddressStorageMode storage_mode_;
 };
-}
-}  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_ARM_INTERFACE_DESCRIPTORS_ARM_H_