s390x: Drop not used allow_hotplug in event-facility

s390-sclp-event-facility creates s390-sclp-events-bus
and immediately sets its allow_hotplug field to 0,
which is NOP since it's already 0 by default.

Also since BUS is not hotpluggable, it's not possible
to call SCLP_EVENT{ DeviceClass::unplug } callback
from qdev_unplug() making this unreachable code,
so drop it as well.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>

hw/s390x/event-facility.c

@@ -333,7 +333,6 @@ static int init_event_facility(SCLPEventFacility *event_facility)
     /* Spawn a new bus for SCLP events */
     qbus_create_inplace(&event_facility->sbus, sizeof(event_facility->sbus),
                         TYPE_SCLP_EVENTS_BUS, sdev, NULL);
-    event_facility->sbus.qbus.allow_hotplug = 0;
 
     quiesce = qdev_create(&event_facility->sbus.qbus, "sclpquiesce");
     if (!quiesce) {
@@ -408,7 +407,6 @@ static void event_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->bus_type = TYPE_SCLP_EVENTS_BUS;
-    dc->unplug = qdev_simple_unplug_cb;
     dc->realize = event_realize;
     dc->unrealize = event_unrealize;
 }