glsl: fix gl_CullDistance xfb linking

this matches the behavior for gl_ClipDistance

ref #7152

Fixes: 0c8492cd3b2 ("glsl: fix location for array subscript")

Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18724>
1 file changed