Instead of checking if the very same bit we want to enable is already
enabled, which obviously doesn't work.
Fixes: fbc0e74bda ("anv: enable graphics pipeline libraries by default")
Acked-by: Nanley Chery <nanley.g.chery@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23039>