freetdm: only notify of released channels when is a voice channel

libs/freetdm/src/ftdm_io.c

@@ -2349,8 +2349,6 @@ static void close_dtmf_debug(ftdm_channel_t *ftdmchan)
 static ftdm_status_t ftdm_channel_clear_vars(ftdm_channel_t *ftdmchan);
 FT_DECLARE(ftdm_status_t) ftdm_channel_done(ftdm_channel_t *ftdmchan)
 {
-	ftdm_sigmsg_t sigmsg;
-	
 	ftdm_assert_return(ftdmchan != NULL, FTDM_FAIL, "Null channel can't be done!\n");
 
 	ftdm_mutex_lock(ftdmchan->mutex);
@@ -2389,12 +2387,15 @@ FT_DECLARE(ftdm_status_t) ftdm_channel_done(ftdm_channel_t *ftdmchan)
 
 	ftdm_log(FTDM_LOG_DEBUG, "channel done %u:%u\n", ftdmchan->span_id, ftdmchan->chan_id);
 
+	if (FTDM_IS_VOICE_CHANNEL(ftdmchan)) {
+		ftdm_sigmsg_t sigmsg;
 		memset(&sigmsg, 0, sizeof(sigmsg));
 		sigmsg.span_id = ftdmchan->span_id;
 		sigmsg.chan_id = ftdmchan->chan_id;
 		sigmsg.channel = ftdmchan;
 		sigmsg.event_id = FTDM_SIGEVENT_RELEASED;
 		ftdm_span_send_signal(ftdmchan->span, &sigmsg);
+	}
 
 	ftdm_mutex_unlock(ftdmchan->mutex);