more clenaup, expect more bugs

funcs/sfx0.c

@@ -33,6 +33,9 @@ for (foo=0; foo<nbpix; foo++) {
 return 0;
 }
 /* --------------------------------------------------------------------- */
+/*
+ *	parameter fval is not used, why ?
+ */
 int fimg_killcolors_b(FloatImg *fimg, float fval)
 {
 int		nbpix, foo;