Unlike the usual object_property_add_link() invocations in other
devices, ivshmem checks the "is mapped" state of the backend in addition
to qdev_prop_allow_set_link_before_realize. To convert it without
specializing DEFINE_PROP_LINK which always uses the qdev callback, move
the extra check to device realize time.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170714021509.23681-12-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>