vulkan/wsi/wayland: always initialize format vector

vulkan/wsi/wayland: always initialize format vector

In wsi_wl_display_init(), the format vector is initialized only when the
caller sets the function to query the formats/modifiers. But
wsi_wl_display_finish() always release the vector, no matter if it has
been initialized or not.

For now it just works because the u_vector_foreach() macro works when
the format vector is uninitialized, but it is a weird design to try to
release something that has not been initialized.

So in this patch we start to always initialize the format vector, even
when not querying formats/modifiers.

Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Acked-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12117>