re-checking that there are no connections before notifying session teardown

Signed-off-by: Eyal Salomon <esalomon@mellanox.com>
responses that are sent when connection is closing should be released and
discarded.

Signed-off-by: Eyal Salomon <esalomon@mellanox.com>
Merge branch 'for_next' of github.com:accelio/accelio into for_next