lockinuse
KKASSERT(!lockinuse(&head->table_mtx));
KKASSERT(lockinuse(l));
#define mutex_is_locked(lock) (lockinuse(lock))
#define assert_spin_locked(x) KKASSERT(lockinuse(x))
if (lockinuse(&vp->v_lock))
KKASSERT(lockinuse(&vp->v_lock));
return (lockinuse(&(bp)->b_lock));
return lockinuse(lkp);