init trace for work queue in dog command

when extrace `wq_trace_init` from `init_work_queue`,
we need to call `wq_trace_init` before `init_work_queue`
so that dog's new thread can work properly.

Signed-off-by: Jinzhi Chen <nxtjinzhi@gmail.com>
Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>