[tests] limit logging to error

dune/stuff/test/function.cc

@@ -111,5 +111,6 @@ TYPED_TEST(SeparableTest, Separable)
 int main(int argc, char** argv)
 {
   testing::InitGoogleTest(&argc, argv);
+  DSC::Logger().create(DSC::LOG_CONSOLE | DSC::LOG_ERROR);
   return RUN_ALL_TESTS();
 }

dune/stuff/test/function_expression.cc

@@ -132,5 +132,6 @@ int main(int argc, char** argv)
 {
   testing::InitGoogleTest(&argc, argv);
   Dune::MPIHelper::instance(argc, argv);
+  DSC::Logger().create(DSC::LOG_CONSOLE | DSC::LOG_ERROR);
   return RUN_ALL_TESTS();
 }