java: simplify the getMSF() methods

Change-Id: Ib459799f4a3224f8c9683ac4b6cf37982d2077a3
Reviewed-on: https://gerrit.libreoffice.org/13406
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>