Simple g_autofree is not enough if we put allocated
data into the device structure.

Define the AUTOPTR_CLEANUP function and use it here.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reported-by: NXu Yandong <xuyandong2@huawei.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>