venus: adopt common android u_gralloc helpers

Drop explicit u_gralloc init since it will be initialized upon the
initial vk_android_get_ugralloc.

Reviewed-by: Corentin Noël <corentin.noel@collabora.com>
Acked-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35561>
1 file changed