Remove dup DE_CONST #define

lib/isccc/include/isccc/util.h

@@ -202,19 +202,4 @@
 		(r).rend = (r).rstart + strlen(s); \
 } while (0)
 
-/*%
- * Use this to remove the const qualifier of a variable to assign it to
- * a non-const variable or pass it as a non-const function argument ...
- * but only when you are sure it won't then be changed!
- * This is necessary to sometimes shut up some compilers
- * (as with gcc -Wcast-qual) when there is just no other good way to avoid the
- * situation.
- */
-#define DE_CONST(konst,var) \
-	do { \
-		union { const void*       k; void*v; } _u; \
-		_u.k = konst; \
-		var = _u.v; \
-	} while (0)
-
 #endif /* ISCCC_UTIL_H */