encoder: avoid GstVaapiCodedBuffer redefinition
encoder: avoid GstVaapiCodedBuffer redefinition

The symbol GstVaapiCodedBuffer is already defined in
gst-libs/gst/vaapi/gstvaapicodedbuffer.h which is loaded, at the end, by
gstvaapiencoder_objects.h. Clang complains about the symbol re-definition.

This patch removes that redefinition.

https://bugzilla.gnome.org/show_bug.cgi?id=747312

CapOM/gstreamer-vaapi,01org/iotg-lin-gfx-gstreamer-vaapi,CapOM/gstreamer-vaapi,ceyusa/gstreamer-vaapi,GStreamer/gstreamer-vaapi,ceyusa/gstreamer-vaapi,01org/iotg-lin-gfx-gstreamer-vaapi,gbeauchesne/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi,01org/iotg-lin-gfx-gstreamer-vaapi,GStreamer/gstreamer-vaapi,CapOM/gstreamer-vaapi