When switching from a normal texture to a texture storage, unreference
the old one to avoid leaking it.
v2 (Emma):
- Update commit message
Reviewed-by: Emma Anholt <emma@anholt.net> Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10643>