Reduce RSIZE_MAX to make range checks effective.

Limiting to 128 MiB as anything larger is very likely an error. If this
is too restrictive it will need to be relaxed.

Change-Id: Id2540242bbd950afe6f981c8526722dc1563ab3d
diff --git a/inc/hf/std.h b/inc/hf/std.h
index 356e61d..be3b168 100644
--- a/inc/hf/std.h
+++ b/inc/hf/std.h
@@ -20,7 +20,12 @@
 
 typedef size_t rsize_t;
 
-#define RSIZE_MAX SIZE_MAX
+/**
+ * Restrict the maximum range for range checked functions so as to be more
+ * likely to catch errors. This may need to be relaxed if it proves to be overly
+ * restrictive.
+ */
+#define RSIZE_MAX (128 * 1024 * 1024)
 
 /*
  * Only the safer versions of these functions are exposed to reduce the chance