[presubmit] Enable readability/namespace linter checking.

src/arm/assembler-arm-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 648 matching lines @@
            IsOrrImmed(Memory::int32_at(pc + kInstrSize)) &&
            IsOrrImmed(Memory::int32_at(pc + 2 * kInstrSize)) &&
            IsOrrImmed(Memory::int32_at(pc + 3 * kInstrSize)));
     if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
       Assembler::FlushICacheWithoutIsolate(pc, 4 * kInstrSize);
     }
   }
 }
 
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_ARM_ASSEMBLER_ARM_INL_H_