Set TX read output

Author: Cuda-Chen

virtio-snd.c

@@ -758,10 +758,8 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
             virtio_snd_pcm_status_t *response =
                 (virtio_snd_pcm_status_t *) (base + addr);
             response->status = VIRTIO_SND_S_OK;
-            response->latency_bytes =
-                0;           /* TODO: show the actual latency bytes */
-            *plen = ret_len; /* TODO: set the read length of buffer of
-                                          PCM frames */
+            response->latency_bytes = ret_len;
+            *plen = sizeof(virtio_snd_pcm_status_t);
             fprintf(stderr, "TX response\n");
             goto early_continue;
         }