pci: unregister vmstate_pcibus on unplug

PCIBus registers a vmstate during init. Unregister it upon
removal/unplug.

Signed-off-by: Bandan Das <bsd@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/pci/pci.c

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index ed32059..49eca95 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -47,6 +47,7 @@
 static char *pcibus_get_dev_path(DeviceState *dev);
 static char *pcibus_get_fw_dev_path(DeviceState *dev);
 static int pcibus_reset(BusState *qbus);
+static void pci_bus_finalize(Object *obj);
 
 static Property pci_props[] = {
     DEFINE_PROP_PCI_DEVFN("addr", PCIDevice, devfn, -1),
@@ -73,6 +74,7 @@
     .name = TYPE_PCI_BUS,
     .parent = TYPE_BUS,
     .instance_size = sizeof(PCIBus),
+    .instance_finalize = pci_bus_finalize,
     .class_init = pci_bus_class_init,
 };
 
@@ -375,6 +377,12 @@
     return s->parent_dev->config[PCI_SECONDARY_BUS];
 }
 
+static void pci_bus_finalize(Object *obj)
+{
+    PCIBus *bus = PCI_BUS(obj);
+    vmstate_unregister(NULL, &vmstate_pcibus, bus);
+}
+
 static int get_pci_config_device(QEMUFile *f, void *pv, size_t size)
 {
     PCIDevice *s = container_of(pv, PCIDevice, config);