RDMA/hns: Fix uninitialized variable bug

There is a potential execution path in which variable *ret* is returned
without being properly initialized, previously.

Fix this by initializing variable *ret* to 0.

Link: https://lore.kernel.org/r/20200328023539.GA32016@embeddedor
Addresses-Coverity-ID: 1491917 ("Uninitialized scalar variable")
Fixes: 2f49de21 ("RDMA/hns: Optimize mhop get flow for multi-hop addressing")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hns/hns_roce_hem.c

@@ -603,7 +603,7 @@ static int set_mhop_hem(struct hns_roce_dev *hr_dev,
 {
 	struct ib_device *ibdev = &hr_dev->ib_dev;
 	int step_idx;
-	int ret;
+	int ret = 0;
 
 	if (index->inited & HEM_INDEX_L0) {
 		ret = hr_dev->hw->set_hem(hr_dev, table, obj, 0);