I noticed we crashed piglit arb_texture_view-rendering-formats
when run on softpipe.
This fixes the clear tiles to use the surface format not the
underlying storage format.
This fixes a bunch of srgb piglits as well.
Fixes: 396ac41fc2 (softpipe: add integer support)
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>