Bugfix: Don't use eventfdDesc after stop()

We call stop() inside the assembleFrameReq3, so when it returns,
the eventfdDesc should be destroyed. Don't allow a possibly stale
eventfdDesc obj to permit us to re-arm the eventfdDesc read_some
call.

stimBuffApis/livoxGen1/ioUringAssemblyEngine.cpp

@@ -587,17 +587,15 @@ void IoUringAssemblyEngine::onEventfdRead(
 		}
 	}
 
+	if (!isAssembling) { return; }
+
 	// Re-arm the eventfd read for next CQE notification
-	// Only re-arm if assembly is still active (stop() hasn't been called)
-	if (eventfdDesc && eventfdFd >= 0)
-	{
-		eventfdDesc->async_read_some(
-			boost::asio::buffer(&eventfd_value, sizeof(eventfd_value)),
-			std::bind(
-				&IoUringAssemblyEngine::onEventfdRead, this,
-				std::placeholders::_1,
-				std::placeholders::_2));
-	}
+	eventfdDesc->async_read_some(
+		boost::asio::buffer(&eventfd_value, sizeof(eventfd_value)),
+		std::bind(
+			&IoUringAssemblyEngine::onEventfdRead, this,
+			std::placeholders::_1,
+			std::placeholders::_2));
 }
 
 void IoUringAssemblyEngine::cancelIncompleteAndFillDummies()