Add missing return in nonvoid functions #2

The Open Build Service linter complains about missing returns in non-void functions.
This patch add the returns.

One occurrence seems incorrect. Please check it.

It seems good.

     realFunction(chooser);
     if (((kgtkApp == APP_UNKNOWN) && BLACKLIST_UNKNOWN_GTK_APPS) || (kgtkApp == APP_BLACKLISTED) && realFunction) {
         return;
         return FALSE;