fix a bug in workqueue.c where we weren't iterating over global_cwq's
correctly.

Still have a bug where doing late initialization [due to requirements of
TCM memory setup] of tcm_global_cwq / system_tcm_wq causes a deadlock
(from securecrypt.c) when scheduling work.  My guess is the intial
worker that gets setup also gets woken up (but no in late intialization
case).