Exploit r288122 to address a cosmetic issue. Pages belonging to either
the kernel or kmem object can't be paged out. Since they can't be paged
out, they are never enqueued in a paging queue. Nonetheless, passing
PQ_INACTIVE to vm_page_unwire() in kmem_unback() creates the appearance
that these pages are being enqueued in the inactive queue. As of r288122,
we can avoid giving this false impression by passing PQ_NONE.

Submitted by: kmacy
Differential Revision: https://reviews.freebsd.org/D1674