RDMA/hns: Fix uninitialized ucmd in hns_roce_create_qp_common()

ucmd in hns_roce_create_qp_common() are not initialized. But it works fine
until new member sdb_addr is added to struct hns_roce_ib_create_qp.

If the user-mode driver uses an old version ABI, then the value of the new
member will be undefined after ib_copy_from_udata().

This patch fixes it by initialize this variable to 0. And the default value
of the new member sdb_addr will be 0 which is invalid.

Fixes: 0425e3e6 ("RDMA/hns: Support flush cqe for hip08 in kernel space")
Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20231017125239.164455-3-huangjunxian6@hisilicon.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/hns/hns_roce_qp.c

@@ -1064,7 +1064,7 @@ static int hns_roce_create_qp_common(struct hns_roce_dev *hr_dev,
 {
 	struct hns_roce_ib_create_qp_resp resp = {};
 	struct ib_device *ibdev = &hr_dev->ib_dev;
-	struct hns_roce_ib_create_qp ucmd;
+	struct hns_roce_ib_create_qp ucmd = {};
 	int ret;
 
 	mutex_init(&hr_qp->mutex);