lif: rename internal types and constants generated by cgo

To match up with other packages that work with IP protocol stack.

Change-Id: Idc3ee5b2399c4982dbd9114aac441f6d7452aeef
Reviewed-on: https://go-review.googlesource.com/30576
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
4 files changed