ac/nir/ngg: remove nuw for negative value add
Add negative value is possible to wrap around. I haven't seen this "nuw" causes any problem yet, but let's remove it for safe. Fixes: 60ac5dda ("ac: Add NIR lowering for NGG GS.") Reviewed-by:Timur Kristóf <timur.kristof@gmail.com> Signed-off-by:
Qiang Yu <yuq825@gmail.com> Part-of: <mesa/mesa!19718>