Fix unlikely leaks

src/hb-ot-shape.cc

diff --git a/src/hb-ot-shape.cc b/src/hb-ot-shape.cc
index 6696ad8..70c9c63 100644
--- a/src/hb-ot-shape.cc
+++ b/src/hb-ot-shape.cc
@@ -193,8 +193,10 @@
 
   if (plan->shaper->data_create) {
     plan->data = plan->shaper->data_create (plan);
-    if (unlikely (!plan->data))
+    if (unlikely (!plan->data)) {
+      free ((void*)plan);
       return nullptr;
+    }
   }
 
   return plan;