hw/s390x/event-facility: Use the QOM BUS() macro to access BusState.qbus

Rather than looking inside the definition of a BusState with "s->bus.qbus",
use the QOM prefered style: "BUS(&s->bus)".

This patch was generated using the following Coccinelle script:

    // Use BUS() macros to access BusState.qbus
    @use_bus_macro_to_access_qbus@
    expression obj;
    identifier bus;
    @@
    -&obj->bus.qbus
    +BUS(&obj->bus)
Suggested-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Message-Id: <20190528164020.32250-5-philmd@redhat.com>
Signed-off-by: NLaurent Vivier <laurent@vivier.eu>

hw/s390x/event-facility.c

@@ -466,12 +466,12 @@ static void init_event_facility(Object *obj)
     new = object_new(TYPE_SCLP_QUIESCE);
     object_property_add_child(obj, TYPE_SCLP_QUIESCE, new, NULL);
     object_unref(new);
-    qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
+    qdev_set_parent_bus(DEVICE(new), BUS(&event_facility->sbus));
 
     new = object_new(TYPE_SCLP_CPU_HOTPLUG);
     object_property_add_child(obj, TYPE_SCLP_CPU_HOTPLUG, new, NULL);
     object_unref(new);
-    qdev_set_parent_bus(DEVICE(new), &event_facility->sbus.qbus);
+    qdev_set_parent_bus(DEVICE(new), BUS(&event_facility->sbus));
     /* the facility will automatically realize the devices via the bus */
 }