drm-misc-fixes for v6.7-rc1:

qxl:
- qxl memory leak fix.
syncobj:
- Fix waiting for DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE
vc4:
- Fix UAF in mock helpers
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[sima: Stitch together both changelogs from Maarten. Also because of
branch history this contains a few more bugfixes which are already in
v6.6, but I didn't feel like this justifies some backmerge since there
wasn't any real conflict.]
Link: https://patchwork.freedesktop.org/patch/msgid/bc8598ee-d427-4616-8ebd-64107ab9a2d8@linux.intel.com