increasing the size of the namecache suddenly made the comment

increasing the size of the namecache suddenly made the comment
"This makes the algorithm O(n^2), but do you think I care?"
a lot more meaningful, as discovered by krw.
fix the loop so it doesn't restart all the time, as it's not necessary.
(this was also tried years ago in rev 1.20 and reverted, but that change
also introduced pool_put before the namecache was ready to free things. we
have been freeing cache entries with pool_put for some time now, so that's
been made safe.)
ok deraadt krw