Use OBJECT_DECLARE_TYPE where possible

Replace DECLARE_OBJ_CHECKERS with OBJECT_DECLARE_TYPE where the
typedefs can be safely removed.

Generated running:

$ ./scripts/codeconverter/converter.py -i \
  --pattern=DeclareObjCheckers $(git grep -l '' -- '*.[ch]')

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200831210740.126168-16-ehabkost@redhat.com>
Message-Id: <20200831210740.126168-17-ehabkost@redhat.com>
Message-Id: <20200831210740.126168-18-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h
index 35fec7c..e0e6750 100644
--- a/include/hw/xen/xen-bus.h
+++ b/include/hw/xen/xen-bus.h
@@ -71,17 +71,15 @@
     XenWatch *backend_watch;
     QLIST_HEAD(, XenDevice) inactive_devices;
 };
-typedef struct XenBus XenBus;
 
 struct XenBusClass {
     /*< private >*/
     BusClass parent_class;
 };
-typedef struct XenBusClass XenBusClass;
 
 #define TYPE_XEN_BUS "xen-bus"
-DECLARE_OBJ_CHECKERS(XenBus, XenBusClass,
-                     XEN_BUS, TYPE_XEN_BUS)
+OBJECT_DECLARE_TYPE(XenBus, XenBusClass,
+                    xen_bus, XEN_BUS)
 
 void xen_bus_init(void);