[pulse] rewrite test to avoid stack variable address escape

Summary: Pulse is about to be smart enough to detect that bug.

Reviewed By: da319

Differential Revision: D13466895

fbshipit-source-id: 79afd2d51

infer/tests/codetoanalyze/cpp/pulse/use_after_destructor.cpp

@@ -247,7 +247,8 @@ std::unique_ptr<A>* allocate_in_branch_ok(bool b) {
     a3 = &a2;
   }
 
-  return a3;
+  // read a3
+  const B* read = (*a3)->f;
 }
 
 } // namespace use_after_destructor