[Bug]:A potential goleak

[xuxiaofan1203]

blocking position:

libnetwork/networkdb/cluster.go

Line 257 in 3797618

case <-nDB.ctx.Done():

The nDB.cancelCtx() is in the func clusterLeave(), when return err ,the cancelFunc can't get executed and the goroutine leak.

libnetwork/networkdb/cluster.go

Lines 224 to 243 in 3797618

	func (nDB *NetworkDB) clusterLeave() error {
	mlist := nDB.memberlist
	if err := nDB.sendNodeEvent(NodeEventTypeLeave); err != nil {
	logrus.Errorf("failed to send node leave: %v", err)
	}
	if err := mlist.Leave(time.Second); err != nil {
	return err
	}
	// cancel the context
	nDB.cancelCtx()
	for _, t := range nDB.tickers {
	t.Stop()
	}
	return mlist.Shutdown()
	}

You can reproduce the bug by making program execute the path and test it by goleak