st/mesa: use uint-result for sampling stencil buffers
Otherwise, we end up mismatching the result-type and the sampler-type.
Fixes: 642125ed ("st/mesa: use uint-samplers for sampling stencil buffers")
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
Otherwise, we end up mismatching the result-type and the sampler-type.
Fixes: 642125ed ("st/mesa: use uint-samplers for sampling stencil buffers")