memory-device: trace when pre_plugging/plugging/unplugging

memory-device: trace when pre_plugging/plugging/unplugging

Let's trace the address and the id of a memory device when
pre_plugging/plugging/unplugging succeeded.

Trace it when pre_plugging as well as when plugging, so we really know
when a specific address is actually used.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181005092024.14344-17-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>