These buffers aren't known to the actual OMX codec.

Normally, these buffers are removed from the queue by
DecodeAudio/DecodeVideo, but if they're pushed multiple
times (which happens when using google sw decoders),
PortReconfigure might try to free them.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
(cherry picked from commit 6643ac0ae02a61c95b3911b1c36856ace0d06b2e)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>