tests: Use MakeUnique to construct objects owned by unique_ptrs

src/test/allocator_tests.cpp

@@ -163,7 +163,7 @@ private:
 BOOST_AUTO_TEST_CASE(lockedpool_tests_mock)
 {
     // Test over three virtual arenas, of which one will succeed being locked
-    std::unique_ptr<LockedPageAllocator> x(new TestLockedPageAllocator(3, 1));
+    std::unique_ptr<LockedPageAllocator> x = MakeUnique<TestLockedPageAllocator>(3, 1);
     LockedPool pool(std::move(x));
     BOOST_CHECK(pool.stats().total == 0);
     BOOST_CHECK(pool.stats().locked == 0);