RFR: 8249264: Build validate-headers task fails after JDK-8248261

[igor.ignatyev at oracle.com]

LGTM

— Igor

> On Jul 13, 2020, at 5:35 PM, alexander.matveev at oracle.com wrote:
> 
> Please review the jpackage fix for bug [1] at [2].
> 
> Added missing ",".
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8249264
> [2] http://cr.openjdk.java.net/~almatvee/8249264/webrev.00/
> 
> Thanks,
> Alexander