pan/decode: Free mapped memory objects on BO unreference

Cc: mesa-stable
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8583>
(cherry picked from commit 0d0536c1a7662e2c1d99d221c444bc19ca3ab566)
4 files changed