ctdb-daemon: Switch banning code to use ctdb_node_become_inactive()

ctdb-daemon: Switch banning code to use ctdb_node_become_inactive()

There's no reason to avoid immediately setting recovery mode to active
and initiating freeze of databases.

This effectively reverts the following commits:

  d8f3b490bbb691c9916eed0df5b980c1aef23c85
  b4357a79d916b1f8ade8fa78563fbef0ce670aa9

The latter is now implemented using a control, resulting in looser
coupling.

See also the following commit:

  f8141e91a693912ea1107a49320e83702a80757a

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14087

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