vdec: also set proper b->len when appropriate in (h264 nal) transformation
vdec: also set proper b->len when appropriate in (h264 nal) transformation

Signed-off-by: Mark Nauwelaerts <b7a9d5e0b6d7b100d27ef2a8e80c5c1c14a8de12@collabora.co.uk>

community-ssu/gst-dsp,community-ssu/gst-dsp,felipec/gst-dsp,felipec/gst-dsp,community-ssu/gst-dsp