RDMA/cm: Fix an error check in cm_alloc_id_priv()

The xa_alloc_cyclic_irq() function returns either 0 or 1 on success and
negatives on error.  This code treats 1 as an error and returns ERR_PTR(1)
which will cause an Oops in the caller.

Fixes: ae78ff3 ("RDMA/cm: Convert local_id_table to XArray")
Link: https://lore.kernel.org/r/20200407093714.GA80285@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/cm.c

@@ -862,7 +862,7 @@ static struct cm_id_private *cm_alloc_id_priv(struct ib_device *device,
 
 	ret = xa_alloc_cyclic_irq(&cm.local_id_table, &id, NULL, xa_limit_32b,
 				  &cm.local_id_next, GFP_KERNEL);
-	if (ret)
+	if (ret < 0)
 		goto error;
 	cm_id_priv->id.local_id = (__force __be32)id ^ cm.random_id_operand;