RDMA/siw: Release xarray entry

The xarray entry is allocated in siw_qp_add(), but release was
missed in case zero-sized SQ was discovered.

Fixes: 661f3859 ("RDMA/siw: Fix handling of zero-sized Read and Receive Queues.")
Link: https://lore.kernel.org/r/f070b59d5a1114d5a4e830346755c2b3f141cde5.1620560472.git.leonro@nvidia.comSigned-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/sw/siw/siw_verbs.c

@@ -375,7 +375,7 @@ struct ib_qp *siw_create_qp(struct ib_pd *pd,
 	else {
 		/* Zero sized SQ is not supported */
 		rv = -EINVAL;
-		goto err_out;
+		goto err_out_xa;
 	}
 	if (num_rqe)
 		num_rqe = roundup_pow_of_two(num_rqe);