mesa: fix/change state validation order for program/texture state

mesa: fix/change state validation order for program/texture state

Program state needs to be updated before texture state since the later depends
on the former.

Fixes piglit texgen failure.  The second time through the modes (press 't'
three times) we disable the fragment program and return to conventional texture
mode.  State validation failed here because update_texture() saw stale fragment
program state.