zink: fix conditional when assigning tess variable io

this was not copied directly and changed the old conditional, which
was intended to catch only non-patch tess io

fixes tess io with legacy builtins, e.g., spec@!opengl 2.0@vertex-program-two-side back front2 back2

Fixes: 2d98efd3232 ("zink: pre-populate locations in variables")

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9996>
1 file changed