[illumos-Developer] Review: 417 Stale OpenOwner entries are not reaped for active clients

[Albert Lee]

There's a resource leak in NFSv4 that I've finally verified a fix for.
OpenOwner table entries past their lease time are not destroyed as
long as there is any client activity, and server stops responding at
1M entries.

http://www.illumos.org/issues/417

Webrev is here:
http://pkgdev.openindiana.org/~trisk/417/il_417_openowner_expiry/

I'm unsure whether the last change to
rfs4_state_expiry should be more conservative (it's not necessary for the fix).

-Albert