xnbd: Add new device to devs_list only when successfully created

We can avoid taking care of removing it in error flows.

Signed-off-by: Milind Dumbare <milind.dumbare@profitbricks.com>
Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
raio_kutils: Escalate signed errno from raio response

Escalating unsigned errno causes xx_store() routines
to be called multiple times.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reported-by: Milind Dumbare <milind.dumbare@profitbricks.com>