[presubmit] Enable readability/namespace linter checking.

src/arm64/macro-assembler-arm64-inl.h

 // Copyright 2013 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_ARM64_MACRO_ASSEMBLER_ARM64_INL_H_
 #define V8_ARM64_MACRO_ASSEMBLER_ARM64_INL_H_
 
 #include <ctype.h>
 
 #include "src/globals.h"
@@ skipping 1665 matching lines @@
   DCHECK(strlen(marker_name) == 2);
 
   // We allow only printable characters in the marker names. Unprintable
   // characters are reserved for controlling features of the instrumentation.
   DCHECK(isprint(marker_name[0]) && isprint(marker_name[1]));
 
   InstructionAccurateScope scope(this, 1);
   movn(xzr, (marker_name[1] << 8) | marker_name[0]);
 }
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_ARM64_MACRO_ASSEMBLER_ARM64_INL_H_