llvm/unittests: Use OwningPtr to fix --vg-leak.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173240 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/IR/DominatorTreeTest.cpp b/unittests/IR/DominatorTreeTest.cpp
index a378f2c..4e5af93 100644
--- a/unittests/IR/DominatorTreeTest.cpp
+++ b/unittests/IR/DominatorTreeTest.cpp
@@ -191,7 +191,7 @@
 
     TEST(DominatorTree, Unreachable) {
       DPass *P = new DPass();
-      Module *M = makeLLVMModule(P);
+      OwningPtr<Module> M(makeLLVMModule(P));
       PassManager Passes;
       Passes.add(P);
       Passes.run(*M);