Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)

Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
diff --git a/llvm/lib/ProfileData/CoverageMappingReader.cpp b/llvm/lib/ProfileData/CoverageMappingReader.cpp
index 43d5ecf..334a3f5 100644
--- a/llvm/lib/ProfileData/CoverageMappingReader.cpp
+++ b/llvm/lib/ProfileData/CoverageMappingReader.cpp
@@ -315,7 +315,7 @@
     return std::error_code();
   }
 };
-} // namespace
+}
 
 template <typename T, support::endianness Endian>
 std::error_code readCoverageMappingData(