hg: jdk/jdk: 8206962: jlink --release-info=del throws NPE if no keys are specified

[sundararajan.athijegannathan at oracle.com]

Changeset: 9144c0b5c1e1
Author:    sundar
Date:      2018-12-05 19:22 +0530
URL:       http://hg.openjdk.java.net/jdk/jdk/rev/9144c0b5c1e1

8206962: jlink --release-info=del throws NPE if no keys are specified
Reviewed-by: alanb

! src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/ReleaseInfoPlugin.java
! test/jdk/tools/jlink/JLinkTest.java