Test failure with `back11` in test `OrthogonalDeferredEuml.cpp`

After having added test cases to cover all existing backends in #84 I identified a test failure in `OrthogonalDeferredEuml.cpp` when utilizing `back11`.

I suspect the error lies within the backend and is not related to my refactoring, because the other backend variants for this test and all other tests in general work fine.

The test output is as follows:

```
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(326): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": AllOk should be active
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(328): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": ErrorMode exit not called correctly
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(330): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": AllOk entry not called correctly
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(333): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": Playing should be active
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(335): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": Stopped exit not called correctly
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(336): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": Playing entry not called correctly
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(339): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": AllOk should be active
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(341): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": ErrorTerminate should be active
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(343): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": AllOk exit not called correctly
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(345): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": ErrorTerminate entry not called correctly
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(349): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": ErrorTerminate should be active
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(352): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": Playing should be active
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(358): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": ErrorTerminate should be active
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(359): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": Playing should be active
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(365): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": ErrorTerminate should be active
/home/xubuntu/ProgrammingVsCode/msm/test/OrthogonalDeferredEuml.cpp(366): error: in "orthogonal_deferred_euml_test<(anonymous namespace)__hierarchical_state_machine>": Playing should be active
```