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/InstCount.cpp b/llvm/lib/Analysis/InstCount.cpp
index de2b9c0..e76d26e 100644
--- a/llvm/lib/Analysis/InstCount.cpp
+++ b/llvm/lib/Analysis/InstCount.cpp
@@ -64,7 +64,7 @@
     void print(raw_ostream &O, const Module *M) const override {}
 
   };
-}
+} // namespace
 
 char InstCount::ID = 0;
 INITIALIZE_PASS(InstCount, "instcount",