nine: state: fix COPY_PASTE_ERROR

Copy-paste error  (COPY_PASTE_ERROR)
/src/gallium/state_trackers/nine/nine_state.c: 403 in update_constants()

Signed-off-by: Axel Davy <axel.davy@ens.fr>
Signed-off-by: David Heidelberg <david@ixit.cz>