[sfnt] Fix previous commit.

Problems reported as

  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40

We now map the strike index right before accessing the physical
data, not earlier.

* src/sfnt/sfobjs.c (sfnt_load_face): Set `face->sbit_strike_map'
after creating the map so that...

* src/sfnt/ttsbit.c (tt_face_load_strike_metrics): ... this function
can be used before and after setting up `sbit_strike_map'.
(tt_face_set_sbit_strike): Revert change.
(tt_sbit_decoder_init, tt_face_load_sbix_image): Map strike index.

* src/truetype/ttdriver.c (tt_size_select): Revert change.
4 files changed