ffmpeg: print command replies starting on column 0

This fixes formating issues with multi-line replies
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

ffmpeg.c

@@ -2697,7 +2697,7 @@ static int check_keyboard_interaction(int64_t cur_time)
                     if (time < 0) {
                         ret = avfilter_graph_send_command(fg->graph, target, command, arg, buf, sizeof(buf),
                                                           key == 'c' ? AVFILTER_CMD_FLAG_ONE : 0);
-                        fprintf(stderr, "Command reply for stream %d: ret:%d res:%s\n", i, ret, buf);
+                        fprintf(stderr, "Command reply for stream %d: ret:%d res:\n%s", i, ret, buf);
                     } else {
                         ret = avfilter_graph_queue_command(fg->graph, target, command, arg, 0, time);
                     }