Simplify forking_enable selection

Conflicts:
	celery/worker/components.py

celery/worker/__init__.py

@@ -186,7 +186,7 @@ class Pool(bootsteps.StartStopComponent):
     def create(self, w, semaphore=None, max_restarts=None):
         threaded = not w.use_eventloop
         procs = w.min_concurrency
-        forking_enable = w.no_execv or not w.force_execv
+        forking_enable = w.no_execv if w.force_execv else True
         if not threaded:
             semaphore = w.semaphore = BoundedSemaphore(procs)
             w._quick_acquire = w.semaphore.acquire