RDMA/hns: Fixes missing error code of CMDQ

When posting a multi-descriptors command, the error code of previous
failed descriptors may be rewrote to 0 by a later successful descriptor.

Fixes: a04ff739f2 ("RDMA/hns: Add command queue support for hip08 RoCE driver")
Link: https://lore.kernel.org/r/1612688143-28226-3-git-send-email-liweihang@huawei.com
Signed-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -1317,7 +1317,7 @@ static int __hns_roce_cmq_send(struct hns_roce_dev *hr_dev,
 	u32 timeout = 0;
 	int handle = 0;
 	u16 desc_ret;
-	int ret = 0;
+	int ret;
 	int ntc;
 
 	spin_lock_bh(&csq->lock);
@@ -1361,15 +1361,14 @@ static int __hns_roce_cmq_send(struct hns_roce_dev *hr_dev,
 
 	if (hns_roce_cmq_csq_done(hr_dev)) {
 		handle = 0;
+		ret = 0;
 		while (handle < num) {
 			/* get the result of hardware write back */
 			desc_to_use = &csq->desc[ntc];
 			desc[handle] = *desc_to_use;
 			dev_dbg(hr_dev->dev, "Get cmq desc:\n");
 			desc_ret = le16_to_cpu(desc[handle].retval);
-			if (desc_ret == CMD_EXEC_SUCCESS)
-				ret = 0;
-			else
+			if (unlikely(desc_ret != CMD_EXEC_SUCCESS))
 				ret = -EIO;
 
 			ntc++;