We still do our own cleanup of the LRU map, as we can't drop
any fonts in use.

Change-Id: I8ec5c6ce8f80893635621357e9085950e7010f5b
Reviewed-on: https://gerrit.libreoffice.org/61455
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>