*** TEST POSIX ONCE 01 ***
Init: pthread_once - SUCCESSFUL (init_routine_nesting executes)
Test_init_routine_nesting: invoked
Init: pthread_once - EINVAL (NULL once_control)
Init: pthread_once - EINVAL (NULL init_routine)
Init: pthread_once - SUCCESSFUL (init_routine executes)
Test_init_routine: invoked
Init: pthread_once - SUCCESSFUL (init_routine does not execute)
*** END OF TEST POSIX ONCE 01 ***