fftools/thread_queue: count receive-finished streams as finished

This ensures that tq_receive() will always return EOF after all streams
were receive-finished, even though the sending side might not have
closed them yet. This may allow the receiver to avoid manually tracking
which streams it has already closed.

fftools/thread_queue.c

@@ -177,7 +177,7 @@ static int receive_locked(ThreadQueue *tq, int *stream_idx,
     }
 
     for (unsigned int i = 0; i < tq->nb_streams; i++) {
-        if (!(tq->finished[i] & FINISHED_SEND))
+        if (!tq->finished[i])
             continue;
 
         /* return EOF to the consumer at most once for each stream */