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/IR/User.cpp b/llvm/lib/IR/User.cpp
index 21f4849..522722d 100644
--- a/llvm/lib/IR/User.cpp
+++ b/llvm/lib/IR/User.cpp
@@ -144,4 +144,4 @@
   llvm_unreachable("should never destroy an Operator");
 }
 
-} // namespace llvm
+} // End llvm namespace