PCI/DOE: Fix memory leak with CONFIG_DEBUG_OBJECTS=y

After a pci_doe_task completes, its work_struct needs to be destroyed
to avoid a memory leak with CONFIG_DEBUG_OBJECTS=y.

Fixes: 9d24322e ("PCI/DOE: Add DOE mailbox support functions")
Tested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: stable@vger.kernel.org # v6.0+
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/775768b4912531c3b887d405fc51a50e465e1bf9.1678543498.git.lukas@wunner.deSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/pci/doe.c

@@ -224,6 +224,7 @@ static void signal_task_complete(struct pci_doe_task *task, int rv)
 {
 	task->rv = rv;
 	task->complete(task);
+	destroy_work_on_stack(&task->work);
 }
 
 static void signal_task_abort(struct pci_doe_task *task, int rv)