qdev: Drop misleading qbus_free() function

Same reasoning as commit 02a5c4c9
("qdev: Drop misleading qdev_free() function").  The qbus_free()
function removes the child from the namespace and decrements the
reference count.  It does not, however, guarantee to free the child
since the refcount may still be held.

Just call object_unparent() directly.
Suggested-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>

hw/core/qdev.c

@@ -481,11 +481,6 @@ BusState *qbus_create(const char *typename, DeviceState *parent, const char *nam
     return bus;
 }
 
-void qbus_free(BusState *bus)
-{
-    object_unparent(OBJECT(bus));
-}
-
 static char *bus_get_fw_dev_path(BusState *bus, DeviceState *dev)
 {
     BusClass *bc = BUS_GET_CLASS(bus);
@@ -794,7 +789,7 @@ static void device_unparent(Object *obj)
 
     while (dev->num_child_bus) {
         bus = QLIST_FIRST(&dev->child_bus);
-        qbus_free(bus);
+        object_unparent(OBJECT(bus));
     }
     if (dev->realized) {
         object_property_set_bool(obj, false, "realized", NULL);

hw/pci/pci_bridge.c

@@ -391,7 +391,7 @@ void pci_bridge_exitfn(PCIDevice *pci_dev)
     pci_bridge_region_cleanup(s, s->windows);
     memory_region_destroy(&s->address_space_mem);
     memory_region_destroy(&s->address_space_io);
-    /* qbus_free() is called automatically during device deletion */
+    /* object_unparent() is called automatically during device deletion */
 }
 
 /*

include/hw/qdev-core.h

@@ -283,8 +283,6 @@ void qdev_reset_all(DeviceState *dev);
 void qbus_reset_all(BusState *bus);
 void qbus_reset_all_fn(void *opaque);
 
-void qbus_free(BusState *bus);
-
 /* This should go away once we get rid of the NULL bus hack */
 BusState *sysbus_get_default(void);