RDMA/cma: Deduplicate error flow in cma_validate_port()

Clean up to prepare for the addition of new logic.

Link: https://lore.kernel.org/r/168960674597.3007.6128252077812202526.stgit@manet.1015granger.netSigned-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/cma.c

@@ -686,30 +686,31 @@ cma_validate_port(struct ib_device *device, u32 port,
 		  struct rdma_id_private *id_priv)
 {
 	struct rdma_dev_addr *dev_addr = &id_priv->id.route.addr.dev_addr;
+	const struct ib_gid_attr *sgid_attr = ERR_PTR(-ENODEV);
 	int bound_if_index = dev_addr->bound_dev_if;
-	const struct ib_gid_attr *sgid_attr;
 	int dev_type = dev_addr->dev_type;
 	struct net_device *ndev = NULL;
 
 	if (!rdma_dev_access_netns(device, id_priv->id.route.addr.dev_addr.net))
-		return ERR_PTR(-ENODEV);
+		goto out;
 
 	if ((dev_type == ARPHRD_INFINIBAND) && !rdma_protocol_ib(device, port))
-		return ERR_PTR(-ENODEV);
+		goto out;
 
 	if ((dev_type != ARPHRD_INFINIBAND) && rdma_protocol_ib(device, port))
-		return ERR_PTR(-ENODEV);
+		goto out;
 
 	if (dev_type == ARPHRD_ETHER && rdma_protocol_roce(device, port)) {
 		ndev = dev_get_by_index(dev_addr->net, bound_if_index);
 		if (!ndev)
-			return ERR_PTR(-ENODEV);
+			goto out;
 	} else {
 		gid_type = IB_GID_TYPE_IB;
 	}
 
 	sgid_attr = rdma_find_gid_by_port(device, gid, gid_type, port, ndev);
 	dev_put(ndev);
+out:
 	return sgid_attr;
 }