pds_core: fix use-after-free on workqueue during remove

Summary

In the Linux kernel, the following vulnerability has been resolved: pds_core: fix use-after-free on workqueue during remove In pdsc_remove(), the workqueue is destroyed before pdsc_teardown() is called. This ordering allows two paths to queue work on the destroyed workqueue: 1. If pdsc_teardown() -> pdsc_devcmd_reset() times out, the error path in pdsc_devcmd_locked() queues health_work. 2. A NotifyQ event can trigger the ISR and queue work before free_irq() is called in pdsc_teardown(). Fix by moving destroy_workqueue() after pdsc_teardown() so the workqueue outlives every queuer; destroy_workqueue() then flushes any work still pending. Draining the queued work also requires ordering the teardown so the resources that work touches are freed last: - In pdsc_qcq_free(), after freeing the interrupt, cancel_work_sync() the queue's work and only then clear qcq->intx, so pdsc_process_adminq()'s read of qcq->intx for interrupt-credit return cannot race with the clear. - Free adminqcq before notifyqcq: the shared adminq ISR is released when adminqcq is freed, and the adminq work accesses notifyqcq, so both must be stopped before notifyqcq is freed.