java: unused local vars

Change-Id: Ib0709da830788f8169282e45552af4fdc300ccf9
Reviewed-on: https://gerrit.libreoffice.org/13096
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>