loopout: close sweepbatcher quitChan

This is needed because sweepbatcher can use this channel in multiple
select statements to unblock itself if the caller cancels.

Author: starius

loopout.go

@@ -1148,7 +1148,7 @@ func (s *loopOutSwap) waitForHtlcSpendConfirmedV2(globalCtx context.Context,
 	quitChan := make(chan bool, 1)
 
 	defer func() {
-		quitChan <- true
+		close(quitChan)
 	}()
 
 	notifier := sweepbatcher.SpendNotifier{