use isnull in test

git-svn-id: svn://bind10.isc.org/svn/bind10/trunk@1413 e5f2f494-b856-4b98-b285-d166d9295462

src/lib/config/tests/module_spec_unittests.cc

@@ -66,7 +66,7 @@ TEST(ModuleSpec, ReadingSpecfiles) {
     dd = moduleSpecFromFile(file);
     EXPECT_EQ(dd.getFullSpec()->get("module_name")
                               ->stringValue(), "Spec1");
-    EXPECT_EQ(dd.getCommandsSpec(), ElementPtr());
+    EXPECT_TRUE(isNull(dd.getCommandsSpec()));
 
     std::ifstream file2;
     file2.open(specfile("spec8.spec").c_str());