ctdb-recovery: Terminate if recovery fails without any banning credits

ctdb-recovery: Terminate if recovery fails without any banning credits

In case of database recovery failure, if there are no banning credits
assigned, then the async computation is never terminated.  The else
condition is missing in (max_credits >= NUM_RETRIES) check.

Signed-off-by: Amitay Isaacs <amitay@gmail.com>
Reviewed-by: Martin Schwenke <martin@meltin.net>
Autobuild-User(master): Martin Schwenke <martins@samba.org>
Autobuild-Date(master): Fri Jun 24 09:56:23 CEST 2016 on sn-devel-144