ctdb-tools: New function ctdb_kill_tcp_init()

ctdb-tools: New function ctdb_kill_tcp_init()

This replaces ctdb_killtcp(), which did the initialisation inside a
loop.  The new logic is inverted, making it more natural.

The variable containing all the state is called "state" in
anticipation of the next commit that will convert this to a tevent_req
computation.  This will mean less churn.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>