delete pending close event before calling context shutdown

Signed-off-by: Eyal Salomon <esalomon@mellanox.com>
Adding new utility function memclonev_ex to copy xio_iovec_ex's length
from source iovec to destination iovec

Signed-off-by: Eyal Salomon <esalomon@mellanox.com>
in xio_cq_release, locks should be done only when deleting
the cq from from list

Signed-off-by: Eyal Salomon <esalomon@mellanox.com>