pk: Unlink leftover shm segments in shm_init()
pk: Unlink leftover shm segments in shm_init()

- If there's a shm segment with the same name as the one we're trying to
create, unlink it: it's likely leftover from a previous PK crash

cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr