astobj2: correct define for ao2_t_cleanup

This change maps the ao2_t_cleanup() function to the
correct debug function so that it can be used.

Review: https://reviewboard.asterisk.org/r/3764/



git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@418488 f38db490-d61c-443f-a65b-d21fe96a405b