Fixed/added namespace ending comments using clang-tidy. NFC

The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index bbf0b2b..2fe8db9 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -231,7 +231,7 @@
                       uint32_t GroupSymbolIndex, uint64_t Offset, uint64_t Size,
                       const MCSectionELF &Section);
   };
-}
+} // namespace
 
 void ELFObjectWriter::align(unsigned Alignment) {
   uint64_t Padding = OffsetToAlignment(OS.tell(), Alignment);