CVE-2024-44956 drm/xe/preempt_fence: enlarge the fence critical section

In the Linux kernel, the following vulnerability has been resolved: drm/xe/preemptfence: enlarge the fence critical section It is really easy to introduce subtle deadlocks in preemptfenceworkfunc since we operate on single global ordered-wq for signalling our preempt fences behind the scenes, so...