replacing portalfs kernel driver with puffs

[Antti Kantee <pooka%cs.hut.fi@localhost>]

Hi,

I plan to remove sys/miscfs/portalfs next week and rename
mount_puffsportal to mount_portal.  If you use portalfs, please
doublecheck your portal daemon configs work.  There should be no
user-visible change except that now you can ctrl-c in the calling process
if your portal daemon hangs at initial connect.

  - antti

p.s. please test with a -current or -5 kernel less than a month old
(kern/40570)