This was already being used in handle_frame() for errors that happen when queueing a frame for decoding, let's do the same when a frame is flagged with an error in the output callback. From quick testing, this makes seeking more reliable (previously, it would sometimes cause a decoding error and shut the whole decoder down due to GST_FLOW_ERROR). Also manually sets the max error count to actually stop processing if too many errors occur. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6446>