anv/cmd_buffer: Actually use the stencil dimension

In an attempt to fix 3DSTATE_DEPTH_BUFFER for stencil-only cases, I
accidentally kept setting the SurfaceType to 2D in the stencil-only case
thanks to a copy+paste error.

Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>

src/intel/vulkan/genX_cmd_buffer.c

@@ -2153,7 +2153,7 @@ cmd_buffer_emit_depth_stencil(struct anv_cmd_buffer *cmd_buffer)
        */
       anv_batch_emit(&cmd_buffer->batch, GENX(3DSTATE_DEPTH_BUFFER), db) {
          if (has_stencil) {
-            db.SurfaceType       = SURFTYPE_2D;
+            db.SurfaceType       =
                depth_stencil_surface_type(image->stencil_surface.isl.dim);
          } else {
             db.SurfaceType       = SURFTYPE_2D;