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/Analysis/BlockFrequencyInfoImpl.cpp b/llvm/lib/Analysis/BlockFrequencyInfoImpl.cpp
index 6ceda06..daa77b8 100644
--- a/llvm/lib/Analysis/BlockFrequencyInfoImpl.cpp
+++ b/llvm/lib/Analysis/BlockFrequencyInfoImpl.cpp
@@ -598,7 +598,7 @@
   static ChildIteratorType child_begin(NodeType *N) { return N->succ_begin(); }
   static ChildIteratorType child_end(NodeType *N) { return N->succ_end(); }
 };
-}
+} // namespace llvm
 
 /// \brief Find extra irreducible headers.
 ///