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/Transforms/Utils/FlattenCFG.cpp b/llvm/lib/Transforms/Utils/FlattenCFG.cpp
index 40a48c0..4eb3e3d 100644
--- a/llvm/lib/Transforms/Utils/FlattenCFG.cpp
+++ b/llvm/lib/Transforms/Utils/FlattenCFG.cpp
@@ -46,7 +46,7 @@
   FlattenCFGOpt(AliasAnalysis *AA) : AA(AA) {}
   bool run(BasicBlock *BB);
 };
-} // namespace
+}
 
 /// If \param [in] BB has more than one predecessor that is a conditional
 /// branch, attempt to use parallel and/or for the branch condition. \returns