vaapidecode: simplify copy of GstVideoCodecState
vaapidecode: simplify copy of GstVideoCodecState

Signed-off-by: Víctor Manuel Jáquez Leal <4955886a7d0bd82ff6afce9ed1e93fbb85ab8088@intel.com>

gbeauchesne/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi