radeonsi: fix bounds check in si_create_vertex_elements

This was triggered by
dEQP-GLES3.functional.vertex_array_objects.all_attributes

Cc: "11.1 11.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
1 file changed