aco: fix incorrect address calculation for load_barycentric_at_sample
Fix address calculation for indirect load_barycentric_at_sample on GFX6-8 with a uniform sample index.
A non-zero uniform sample index does not seem to be tested by CTS.
Fix address calculation for indirect load_barycentric_at_sample on GFX6-8 with a uniform sample index.
A non-zero uniform sample index does not seem to be tested by CTS.