Resolves fdo#70681: fixincludeguards.pl: all that's left

Change-Id: I3e51a62710bb46c8255fd228d41d9300c90a1fb5
Reviewed-on: https://gerrit.libreoffice.org/9360
Reviewed-by: Thomas Arnhold <thomas@arnhold.org>
Tested-by: Thomas Arnhold <thomas@arnhold.org>