radeonsi: fix culldist_writemask in nir path

The shared si_create_shader_selector() code already offsets the mask.

Fixes the following piglit tests:

arb_cull_distance/clip-cull-3.shader_test
arb_cull_distance/clip-cull-4.shader_test

Fixes: 29d7bdd179bb (radeonsi: scan NIR shaders to obtain required info)
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
1 file changed