[PATCH] Fix segfault after device assignment hot remove

[Alex Williamson <alex.williamson@redhat.com>]

We keep a qlist of assigned devices for irq updates, but we forgot to
remove entries from it if they're hot unplugged.  This makes
assigned_dev_update_irqs() a timebomb that goes off when the guest is
rebooted.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index 1f13a6d..b9cc06f 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -1390,6 +1390,7 @@ static int assigned_exitfn(struct PCIDevice *pci_dev)
 {
     AssignedDevice *dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
 
+    QLIST_REMOVE(dev, next);
     deassign_device(dev);
     free_assigned_device(dev);
     return 0;