radv/winsys: fix BO list creation when RADV_DEBUG=allbos is set

Fixes: 50fd253b ("radv/winsys: Add priority handling during submit.")
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
(cherry picked from commit 5e18000d)