Log Message:
lsof: disable loading of kernel namecache on NetBSD after 9.99.54

lsof expects to be able to walk the namecache as a linked list using
kmem grovelling. The namecache on NetBSD now uses rbtree instead of
hash buckets + linked list. While it's certainly possible to iterate an
rbtree using kmem it's also more complicated and code doesn't exist yet.
Unfortunately this means lsof for now doesn't resolve pathnames for
type VREG.