daemon: stream: don't update events if stream->closed

Calling virStreamFinish prematurely seems to trigger this code path
even after the stream is closed, which ends up hitting this error
message later:

error : virFDStreamUpdateCallback:127 : internal error: stream is not open

Skip this function if stream->closed, which is used in many other places
like read/write handlers

daemon/stream.c

@@ -76,6 +76,8 @@ static void
 daemonStreamUpdateEvents(daemonClientStream *stream)
 {
     int newEvents = 0;
+    if (stream->closed)
+        return;
     if (stream->rx)
         newEvents |= VIR_STREAM_EVENT_WRITABLE;
     if (stream->tx && !stream->recvEOF)