zink: only add deferred barrier on fb unbind when layout needs to change

this otherwise may have been a surface that was never drawn to or
already had its layout corrected, in which case a deferred barrier
is not only unnecessary, it might be broken

cc: mesa-stable

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21739>
(cherry picked from commit e0dfe058c4c86e23569d82adc75369d5930d8a1a)
2 files changed