Return a std::unique_ptr from CloneModule. NFC.

llvm-svn: 255078
diff --git a/llvm/unittests/Transforms/Utils/Cloning.cpp b/llvm/unittests/Transforms/Utils/Cloning.cpp
index e22573f..25e322e 100644
--- a/llvm/unittests/Transforms/Utils/Cloning.cpp
+++ b/llvm/unittests/Transforms/Utils/Cloning.cpp
@@ -436,7 +436,7 @@
     IBuilder.CreateRetVoid();
   }
 
-  void CreateNewModule() { NewM = llvm::CloneModule(OldM); }
+  void CreateNewModule() { NewM = llvm::CloneModule(OldM).release(); }
 
   LLVMContext C;
   Module *OldM;