ctdb-tests: Avoid segfault by initializing logging

ctdb-tests: Avoid segfault by initializing logging

Setting DEBUGLEVEL before calling debug_init() causes segmentation
violation with gcc8.  DEBUGLEVEL_CLASS is statically initialized to
debug_class_list_initial which is defined as const.  Only after
debug_init() is called, DEBUGLEVEL_CLASS becomes a talloc'd array.

So before modifying DEBUGLEVEL, ensure debug_init() is called via
setup_logging().  (debug_init is a static function.)

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