IoUringAssmEngn: detect assembly end condition w/eventfdDesc validity

We can simplify and universalize the logic here by acknowledging that
assemblyCycleComplete() will always destroy the current eventfdDesc
object, so we can just check that to see whether we should continue
the assembly cycle.

stimBuffApis/livoxGen1/ioUringAssemblyEngine.h

@@ -47,7 +47,7 @@ public:
 		{ return nSucceeded != 0 && nTotal != 0 && nSucceeded != nTotal; }
 
 private:
-	typedef std::function<void(void*, int, bool&)> resetAndAssembleFrameCbFn;
+	typedef std::function<void(void*, int)> resetAndAssembleFrameCbFn;
 	void resetAndAssembleFrame(resetAndAssembleFrameCbFn onCqeReady);
 	void assemblyCycleComplete();
 	bool stop();