Fixed bug 3996 - Corrupted or over-released critical section on SDL_Quit (SDL_event_watchers_lock)

Andrew

This likely comes down to an additional 'unlock' being called before destroying it, without a matching 'lock'.

src/events/SDL_events.c

@@ -369,7 +369,6 @@ SDL_StopEventLoop(void)
     }
 
     if (SDL_event_watchers_lock) {
-        SDL_UnlockMutex(SDL_event_watchers_lock);
         SDL_DestroyMutex(SDL_event_watchers_lock);
         SDL_event_watchers_lock = NULL;
     }