client: endp fsm: allow cancelling a notify event

There is a use-after-free problem if a 'notify' FSM as passed to
osmo_mgcpc_ep_ci_request() deallocates before the notify event has been
dispatched. To avoid that, add API to allow cancelling a notify.

Change-Id: I41687d7f3a808587ab7f7520f46dcc3c29cff92d
2 files changed