Fix build using GCC 15

max is an rint, which doesn't have a "Low" member.  But max.Value,
which is an ruint, does.

Closes: linbox-team#232

src/kernel/recint/rfiddling.h

@@ -167,7 +167,7 @@ namespace RecInt
     template <size_t K>
     inline rint<K> rint<K>::maxFFLAS() {
         rint<K> max;
-        set_highest_bit(max.Low.Value);
+        set_highest_bit(max.Value.Low.Value);
         return max;
     }