This function cleans up anything that needs it. Eg. the ENGINE_add() function
automatically ensures the list cleanup function is registered to be called
from ENGINE_cleanup(). Similarly, all ENGINE_register_*** functions ensure
ENGINE_cleanup() will clean up after them.
This function cleans up anything that needs it. Eg. the ENGINE_add() function automatically ensures the list cleanup function is registered to be called from ENGINE_cleanup(). Similarly, all ENGINE_register_*** functions ensure ENGINE_cleanup() will clean up after them.