Silence compiler warnings by resetting logger in tests

Compiler complained about unused variables. Use the variable by
discarding it.

dune/dorie/test/test-grid-creation.cc

@@ -22,6 +22,7 @@ int main(int argc, char** argv)
   try{
         // Initialize ALL the things!
 		auto [inifile, log, helper] = Dune::Dorie::Setup::init(argc, argv);
+        log.reset(); // silence compiler warning
 
         const auto dimensions = inifile.get<int>("grid.dimensions");
         if (dimensions == 2) {

dune/dorie/test/test-parameterization.cc

@@ -45,6 +45,7 @@ int main (int argc, char** argv)
   try{
     // Initialize ALL the things!
 		auto [inifile, log, helper] = Dune::Dorie::Setup::init(argc, argv);
+    log.reset(); // silence compiler warning
 
     // setup richards configuration
     Dune::ParameterTree richards_config = Dune::Dorie::Setup::prep_ini_for_richards(inifile);

test/test-mass-conservation.cc

@@ -37,6 +37,7 @@ int main (int argc, char** argv)
   try{
     // Initialize ALL the things!
 		auto [inifile, log, helper] = Dune::Dorie::Setup::init(argc, argv);
+    log.reset(); // silence compiler warning
 
     // setup richards configuration
     Dune::ParameterTree richards_config = Dune::Dorie::Setup::prep_ini_for_richards(inifile);

test/test-simulation-dummy-transport.cc

@@ -51,6 +51,7 @@ int main(int argc, char** argv) {
 
     // Initialize ALL the things!
 		auto [inifile, log, helper] = Dune::Dorie::Setup::init(argc, argv);
+    log.reset(); // silence compiler warning
 
     auto inifile_transport = inifile.sub("transport");