hg: build-infra/jdk8: Have diffjarzip.sh return exit code 0 when the contents are identical

[kelly.ohair at oracle.com]

Changeset: 4627a833e02b
Author:    ohair
Date:      2012-08-15 14:59 +0200
URL:       http://hg.openjdk.java.net/build-infra/jdk8/rev/4627a833e02b

Have diffjarzip.sh return exit code 0 when the contents are identical

! common/bin/diffjarzip.sh