If two threads deserialize the raw object at the same time, the
refcount could be more than 1 temporarily.
This can be reproduced with Granite during the multi-threaded pipeline
cache pre-warm on startup, and also with Dota2.
Fixes: cbab396f54 ("vulkan/pipeline_cache: replace raw data objects on cache insertion of real objects")
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22853>
(cherry picked from commit 8126e0287d)
e16268059d