RDMA/hns: Validate the pkey index

Before query pkey, make sure that the queried index is valid.

Fixes: 9a443537 ("IB/hns: Add driver files for hns RoCE driver")
Link: https://lore.kernel.org/r/20211117145954.123893-1-kamalheib1@gmail.comSigned-off-by: Kamal Heib <kamalheib1@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/hns/hns_roce_main.c

@@ -270,6 +270,9 @@ static enum rdma_link_layer hns_roce_get_link_layer(struct ib_device *device,
 static int hns_roce_query_pkey(struct ib_device *ib_dev, u32 port, u16 index,
 			       u16 *pkey)
 {
+	if (index > 0)
+		return -EINVAL;
+
 	*pkey = PKEY_ID;
 
 	return 0;