CVE-2026-68318: pds_core: fix use-after-free on workqueue during remove

In the Linux kernel, the following vulnerability has been resolved:

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

In pdscremove(), the workqueue is destroyed before pdscteardown() is called. This ordering allows two paths to queue work on the destroyed workqueue:

1. If pdscteardown() -> pdscdevcmdreset() times out, the error path in pdscdevcmdlocked() queues healthwork.

2. A NotifyQ event can trigger the ISR and queue work before freeirq() is called in pdscteardown().

Fix by moving destroyworkqueue() after pdscteardown() so the workqueue outlives every queuer; destroyworkqueue() 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 pdscqcqfree(), after freeing the interrupt, cancelworksync() the queue's work and only then clear qcq->intx, so pdscprocessadminq()'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.