[tests] fix yet more tests

dune/stuff/test/function.cc

@@ -63,8 +63,7 @@ struct SeparableTest : public ::testing::Test
   void check() const
   {
     const std::unique_ptr<InterfaceType> function(
-        Function::create<DomainFieldType, dimDomain, RangeFieldType, dimRange>(
-            FunctionType::id(), FunctionType::createSampleDescription()));
+        FunctionType::createFromDescription(FunctionType::createSampleDescription()));
     if (!function->parametric())
       DUNE_THROW(Dune::InvalidStateException, "ERROR: separable function returned parametric() == false!");
     if (!function->separable())