fixincludeguards.sh: improve regex
fixincludeguards.sh: improve regex

handle the following expression correctly:

endif /* !INCLUDED_TDOC_DATASUPPLIER_HXX */

Change-Id: I0c8b31464c9545bdbbb1371f13134f2cc89aad71

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core