[aat/ankr] Minor

DEFINE_SIZE_MIN is to be used only in rare cases. For fixed-size structs
we want DEFINE_SIZE_STATIC.
diff --git a/src/hb-aat-layout-ankr-table.hh b/src/hb-aat-layout-ankr-table.hh
index 68fa96f..f9d5cd3 100644
--- a/src/hb-aat-layout-ankr-table.hh
+++ b/src/hb-aat-layout-ankr-table.hh
@@ -57,7 +57,7 @@
 				anchors;	/* Offset to the glyph data table */
 
   public:
-  DEFINE_SIZE_MIN (12);
+  DEFINE_SIZE_STATIC (12);
 };
 
 } /* namespace AAT */