[autofit] More clean-ups.

* src/autofit/afhints.h (AF_GlyphHintsRec): Remove the no longer
needed fields `xmin_delta` and `xmax_delta`.

* src/autofit/afhints.c (af_glyph_hints_reload),
src/autofit/afloader.c (af_loader_load_glyph): Updated.
4 files changed