[tests] fixes missing HAVE_DUNE_GRID guards

dune/stuff/test/functions.hh

@@ -63,10 +63,12 @@ protected:
   template <class GridType>
   void dynamic_interface_check(const FunctionImp& func, GridType& grid) const
   {
+#if HAVE_DUNE_GRID
     for (const auto& entity : Common::entityRange(grid.leafGridView()))
       std::unique_ptr<LocalfunctionType> local_func = func.local_function(entity);
-    std::string tp                                  = func.type();
-    std::string nm                                  = func.name();
+#endif
+    std::string tp = func.type();
+    std::string nm = func.name();
   } // ... dynamic_interface_check(...)
 
   void copy_check(const FunctionImp& func) const