Simplify ownership with std::unique_ptr. NFC.

llvm-svn: 215566
diff --git a/llvm/unittests/ExecutionEngine/MCJIT/MCJITObjectCacheTest.cpp b/llvm/unittests/ExecutionEngine/MCJIT/MCJITObjectCacheTest.cpp
index fbbab42..5732908 100644
--- a/llvm/unittests/ExecutionEngine/MCJIT/MCJITObjectCacheTest.cpp
+++ b/llvm/unittests/ExecutionEngine/MCJIT/MCJITObjectCacheTest.cpp
@@ -44,14 +44,15 @@
     ObjMap[ModuleID] = copyBuffer(Obj);
   }
 
-  virtual MemoryBuffer* getObject(const Module* M) {
+  virtual std::unique_ptr<MemoryBuffer> getObject(const Module* M) {
     const MemoryBuffer* BufferFound = getObjectInternal(M);
     ModulesLookedUp.insert(M->getModuleIdentifier());
     if (!BufferFound)
       return nullptr;
     // Our test cache wants to maintain ownership of its object buffers
     // so we make a copy here for the execution engine.
-    return MemoryBuffer::getMemBufferCopy(BufferFound->getBuffer());
+    return std::unique_ptr<MemoryBuffer>(
+        MemoryBuffer::getMemBufferCopy(BufferFound->getBuffer()));
   }
 
   // Test-harness-specific functions