We still only support one single layer though, but this allows
receiving streams that have this structure present even for
single layer streams.
Signed-off-by: Martin Storsjö <martin@martin.st>
In this case len is always at least 1, since it is checked against
RTP_VP9_DESC_REQUIRED_SIZE + 1 and then it is reduced by
RTP_VP9_DESC_REQUIRED_SIZE before entering the has_pic_id check.
Bug-Id: CID 1270811