cmd/goyacc: remove unused functions

Found with honnef.co/go/tools/cmd/unused.

Change-Id: Ie7ee9f687bcec1faa40c890a84666ef6c27d9b77
Reviewed-on: https://go-review.googlesource.com/38176
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
1 file changed