[hvf] Fix macro usage and metrics calculations.

* src/hvf/hvfload.c (hvf_render_callback): Fix glyph loader macro calls
and metrics calculations.
* src/hvf/hvfobjs.c (hvf_refresh_axis_coordinates,
hvf_init_axis_coordinates): Tweak macro usage.
* src/hvf/hvfobjs.h (HVF_RenderContext): Remove `face`.

* include/freetype/ftmoderr.h: Add HVF error base.
4 files changed