[presubmit] Enable readability/namespace linter checking.

src/mips64/assembler-mips64-inl.h

 
 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
@@ skipping 470 matching lines @@
 void Assembler::emit(uint64_t x) {
   if (!is_buffer_growth_blocked()) {
     CheckBuffer();
   }
   *reinterpret_cast<uint64_t*>(pc_) = x;
   pc_ += kInstrSize * 2;
   CheckTrampolinePoolQuick();
 }
 
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_MIPS_ASSEMBLER_MIPS_INL_H_