RDMA/nldev: missing error code in nldev_res_get_doit()

We should return -ENOMEM if the allocation fails.  The current code
accidentally returns success.

Fixes: bf3c5a93c5 ("RDMA/nldev: Provide global resource utilization")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/nldev.c

@@ -499,8 +499,10 @@ static int nldev_res_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 		return -EINVAL;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-	if (!msg)
+	if (!msg) {
+		ret = -ENOMEM;
 		goto err;
+	}
 
 	nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
 			RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_RES_GET),