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

The patch is generated using this command:

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

To reduce churn, not touching namespaces spanning less than 10 lines.

llvm-svn: 240270
diff --git a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
index 49eef23..c794de8 100644
--- a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
@@ -61,7 +61,7 @@
     ID.AddInteger((unsigned) X.getObjKind());
 }
 };
-} // end llvm namespace
+} // namespace llvm
 
 //===----------------------------------------------------------------------===//
 // Reference-counting logic (typestate + counts).
@@ -484,7 +484,7 @@
   IdentifierInfo *getIdentifier() const { return II; }
   Selector getSelector() const { return S; }
 };
-}
+} // namespace
 
 namespace llvm {
 template <> struct DenseMapInfo<ObjCSummaryKey> {
@@ -510,7 +510,7 @@
   }
 
 };
-} // end llvm namespace
+} // namespace llvm
 
 namespace {
 class ObjCSummaryCache {
@@ -4032,4 +4032,6 @@
 
 #undef createCallEffect
 
-}}}
+} // namespace objc_retain
+} // namespace ento
+} // namespace clang