BeOS's loadso backend just reports "BeOS error" via SDL_GetError() if loading a shared library fails, and "Symbol not found" if symbol lookup fails.

This is due to incorrect documentation in The Be Book, which says these functions return B_ERROR on failure...however, load_add_on() actually returns a negative number that can be pushed through strerror() to find out what went wrong (get_image_symbol() may, too, but B_ERROR will work in strerror, too, so it doesn't hurt).

Also: since load_add_on() doesn't actually return B_ERROR, the current test in SDL will return a bogus library handle on failure and call it success.

---ryan.