go.net/ipv4: Disable an example.
go.net/ipv4: Disable an example.

This is an example that isn't executed normally anyway
because the function has arguments. Adding an underscore prefix
makes it easier to exclude it from automated tools.

R=adg, r, dave
CC=golang-dev
http://codereview.appspot.com/6570062

andrewzeneski/go.net,fernandez14/go.net,go-mirrors/go.net,ssor/go.net,polydawn-ports/go.net,gigq/go.net