MT#55283 fix double-free bug

fixes #1688

Change-Id: If1a73381bae0d4f475237b65f0978c33e088cfb6
(cherry picked from commit b3c9278f84)

recording-daemon/stream.c

@@ -81,10 +81,13 @@ static void stream_handler(handler_t *handler) {
 			packet_process(stream, buf, ret); // consumes buf
 		else
 			free(buf);
+
+		buf = NULL;
 	}
 
 	pthread_mutex_unlock(&stream->lock);
-	free(buf);
+	if (buf)
+		free(buf);
 	log_info_call = NULL;
 	log_info_stream = NULL;
 }