avtpcvfpay: Fix zero sized nal issue
This MR has two unrelated fix:
- If the
avtpcvfpay
plugin receives a malformed H.264 buffer, containing a zero-sized NAL unit, it would ending up on an infinite loop creating zero-sized GstBuffers, eventually dying due OOM error. Now the code simply stop extracting NAL units from incoming GstBuffer if one is zero-sized. - While at it, fixed an error message that sounded like success.