Prevent uninitialized fields when new fields are added, and make code look
simpler.

Link: https://lore.kernel.org/r/1582162471-50361-1-git-send-email-liweihang@huawei.comSigned-off-by: NLang Cheng <chenglang@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>