Fix preprocessor condition.
@@ -668,7 +668,7 @@ int yr_arena_save_stream(
YR_ARENA_REF ref;
- #if NDEBUG
+ #if !defined(NDEBUG)
int found = yr_arena_ptr_to_ref(arena, *reloc_ptr, &ref);
// yr_arena_ptr_to_ref returns 0 if the relocatable pointer is pointing
// outside the arena, this should not happen.
