draw/gs: handle extra shader outputs in geometry.

When geometry shader is used with unfilled lines and front face,
we don't handle the extra shader output.

Instead of taking the output from the gs, ask draw for the total
which should give the correct answer.

Fixes a test program attached to:
https://gitlab.freedesktop.org/mesa/mesa/-/issues/8644

Reviewed-by: Brian Paul <brianp@vmware.com>
Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23943>

src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c

@@ -120,7 +120,7 @@ llvm_middle_end_prepare_gs(struct llvm_middle_end *fpme)
          }
       }
 
-      variant = draw_gs_llvm_create_variant(llvm, gs->info.num_outputs, key);
+      variant = draw_gs_llvm_create_variant(llvm, draw_total_gs_outputs(draw), key);
 
       if (variant) {
          list_add(&variant->list_item_local.list, &shader->variants.list);