Update stdlib/src/builtin/uint.mojo

Co-authored-by: soraros <soraros@users.noreply.github.com>
Signed-off-by: martinvuyk <110240700+martinvuyk@users.noreply.github.com>
Signed-off-by: martinvuyk <martin.vuyklop@gmail.com>

stdlib/src/builtin/uint.mojo

@@ -383,7 +383,7 @@ struct UInt(IntLike, _HashableWithHasher):
         Returns:
             The ~self value.
         """
-        return self ^ -1
+        return self ^ Self.MAX
 
     # ===----------------------------------------------------------------------===#
     # In place operations.