warning-return-values-filter.diff: avoid warning (i#58977)
warning-return-values-filter.diff: avoid warning (i#58977)

the code was correct; it was wrongly detected by some gcc versions;
the warning was considered as an error in openSUSE build service;
the change does not cause any harm;

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