RFR: JDK-8221749: Error messages

[Andy Herrick]

Please review the jpackage fix for bug [1] at [2].

This is a fix for the JDK-8200758-branch branch of the open sandbox 
repository (jpackage).

[1] http://cr.openjdk.java.net/~herrick/8221749/

[2] https://bugs.openjdk.java.net/browse/JDK-8221749/

/Andy