drm/v3d: Fix potential memory leak in the performance extension

If fetching of userspace memory fails during the main loop, all drm sync
objs looked up until that point will be leaked because of the missing
drm_syncobj_put.

Fix it by exporting and using a common cleanup helper.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Fixes: bae7cb5d ("drm/v3d: Create a CPU job extension for the reset performance query job")
Cc: Maíra Canal <mcanal@igalia.com>
Cc: Iago Toral Quiroga <itoral@igalia.com>
Cc: stable@vger.kernel.org # v6.8+
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240711135340.84617-4-tursulin@igalia.com


(cherry picked from commit 484de39fa5f5b7bd0c5f2e2c5265167250ef7501)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>