Fixing minor compile issue introduced in merged PR

transcoder/basisu_transcoder.cpp

diff --git a/transcoder/basisu_transcoder.cpp b/transcoder/basisu_transcoder.cpp
index a42fb02..e620619 100644
--- a/transcoder/basisu_transcoder.cpp
+++ b/transcoder/basisu_transcoder.cpp
@@ -16,11 +16,11 @@
 #include "basisu_transcoder.h"
 #include "basisu_containers_impl.h"
 
+#include "basisu_astc_hdr_core.h"
+
 #define BASISU_ASTC_HELPERS_IMPLEMENTATION
 #include "basisu_astc_helpers.h"
 
-#include "basisu_astc_hdr_core.h"
-
 #include <limits.h>
 
 #if defined(_MSC_VER)