- fix loop in TraditionalHierarchyViewer.getDepth() to use
  superInterfaces array in loop

Change-Id: I31782ae94fbbb493882542c2512734ed84508611
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.ui/+/180180
Tested-by: JDT Bot <jdt-bot@eclipse.org>
Reviewed-by: Jeff Johnston <jjohnstn@redhat.com>