Remove visual noise from formula

Change-Id: Ie7503623ad9bec1806345f65b435c7bd94a08c2b
Reviewed-on: https://gerrit.libreoffice.org/8263
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>