Fix some serious pointer-arithmatic-magic-number-unchecked-return eyebleed

Fix some serious pointer-arithmatic-magic-number-unchecked-return eyebleed
that I stumbled into here and got stuck with.  If modern society can get past
selling daughters for cows, surely we can decide to write modern C code in
an "application" that is probably 3 lines of shell/python/cgi away from
talking to the internet in a lot of places.. (This file still needs a lot
more love though)
"oh god yuck" deraadt@
ok tedu@