And instead pass it as an argument to an implementation function.
Otherwise this is thread-unsafe for Calc's threaded calculation,
and transliteration is used in various places in Calc code.

Change-Id: Ibdf95e4b6867ec251618f6ff91e605acb69667c0
Reviewed-on: https://gerrit.libreoffice.org/56290
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>