RFR 8157146: Add debug printlns to tests FieldSetAccessibleTest and VerifyJimage.java

[Sundararajan Athijegannathan]

Please review http://cr.openjdk.java.net/~sundar/8157146/webrev.00/ for
https://bugs.openjdk.java.net/browse/JDK-8157146

This is test only change to debug printlns.

Thanks,

-Sundar