parser BUGFIX memoryleak

If-feature reference feature and this feature has invalid status flag.
diff --git a/src/resolve.c b/src/resolve.c
index 99b4a48..8229367 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -1459,6 +1459,7 @@
             f_size--;
 
             if (r == -1) {
+                free(iff_data);
                 goto error;
             }
         }