xio/rdma : fix some typos in comments and output

Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Eyal Salomon <esalomon@mellanox.com>
use ucalloc to zero the memory, in case there are stale data.

Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Eyal Salomon <esalomon@mellanox.com>