lfstack.go:19: println call ends with newline

Change-Id: I2a903eef80a5300e9014999c2f0bc5d40ed5c735
Reviewed-on: https://go-review.googlesource.com/16836
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>