drm/i915: Move fd_install after last use of fence

drm/i915: Move fd_install after last use of fence

Because eb_composite_fence_create() drops the fence_array reference
after creation of the sync_file, only the sync_file holds a ref to the
fence.  But fd_install() makes that reference visable to userspace, so
it must be the last thing we do with the fence.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Fixes: 00dae4d3d35d ("drm/i915: Implement SINGLE_TIMELINE with a syncobj (v4)")
Cc: <stable@vger.kernel.org> # v5.15+
[tursulin: Added stable tag.]
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230203164937.4035503-1-robdclark@gmail.com