infile is never read and cp is never written.  Both are unneeded.

Change-Id: I0a90bb772a53a580ea4be8e5f0f770da7c1acf3a
Reviewed-on: https://go-review.googlesource.com/19651Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Robert Griesemer <gri@golang.org>