Handle revoking delegations of an expired client

release_openstate() goes through all states of an owner, but doesn't
handle delegation states. It now calls state_deleg_revoke, a new
function, which will revoke the delegation. Changed the existing
deleg_revoke() to not delete the state, instead the callers of
deleg_revoke will do the job of deleting the state.

Signed-off-by: Malahal Naineni <malahal@us.ibm.com>