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/DomPrinter.cpp b/llvm/lib/Analysis/DomPrinter.cpp
index 0c880df..0e0d174 100644
--- a/llvm/lib/Analysis/DomPrinter.cpp
+++ b/llvm/lib/Analysis/DomPrinter.cpp
@@ -78,7 +78,7 @@
     return DOTGraphTraits<DomTreeNode*>::getNodeLabel(Node, G->getRootNode());
   }
 };
-}
+} // namespace llvm
 
 namespace {
 struct DominatorTreeWrapperPassAnalysisGraphTraits {