It was set as done by mistake.

Fixes: bc15d745 ("docs/features: Mark some Vulkan extensions as done")
Signed-off-by: Andres Gomez <agomez@igalia.com>
Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>