[config] Use HB_EXPERIMENTAL_API instead of adhoc HB_EXPERIMENTAL
diff --git a/src/hb-config.hh b/src/hb-config.hh
index c59e17c..98b1e9d 100644
--- a/src/hb-config.hh
+++ b/src/hb-config.hh
@@ -35,7 +35,7 @@
 #include "config.h"
 #endif
 
-#ifndef HB_EXPERIMENTAL
+#ifndef HB_EXPERIMENTAL_API
 #define HB_NO_BEYOND_64K
 #define HB_NO_VAR_COMPOSITES
 #endif