vrend: fix shadow_samp_*_locs index incrementing
Commit 603699f1 ("vrend: Cleanup and fix bug in next_sampler_id tracking") fixed a rendering issue in Factorio but inadvertently changed the indexing behavior for shadow samplers in some related code cleaning.
shadow_samp_*_locs
arrays are currently indexed according to the bit
position of a sampler in samplers_used_mask
and shadow_samp_mask
, so
sampler_index
must be incremented for each sampler, not just for each
shadow sampler.
Fixes: 603699f1 ("vrend: Cleanup and fix bug in next_sampler_id tracking")
Signed-off-by: Ryan Neph ryanneph@google.com