hg: jdk9/dev: 8170576: Silence error message in compare.sh when selecting images

[magnus.ihse.bursie at oracle.com]

Changeset: 6d5d54135451
Author:    ihse
Date:      2016-12-01 10:43 +0100
URL:       http://hg.openjdk.java.net/jdk9/dev/rev/6d5d54135451

8170576: Silence error message in compare.sh when selecting images
Reviewed-by: erikj

! common/bin/compare.sh