[ogg-dev] Bug in oggz-validate with small files

[ogg.k.ogg.k at googlemail.com]

It reports that a file contains no Ogg packet if the file is 1023
bytes or less (I think).
I had a go at fixing it, but the code confuses me I'm afraid. I got so
far as having a
very strong suspicion that the problem lies in ovdata_clear at the end
of read_packet
being called before the "we have packets" has been registered.

For testing, just speexenc a tiny wav file (the bug was found using a
Kate stream,
but it seems to do the same with Speex streams, that's why I reckon
it's liboggz's
fault :))
If you can't repro, I'll send in a stream that triggers it for me.