schema tree FEATURE when in compiled actions and notifs

In YANG 1.1, actions nor notifications do not list when as their substatement. However, the when can be de-facto inherited to the actions/notification by augmenting their parent in data tree. Moreover, in future YANG versions, when substatement is planned even for actions/notifications.

PR  #1229
diff --git a/src/tree_schema_free.c b/src/tree_schema_free.c
index 81693ec..c12253c 100644
--- a/src/tree_schema_free.c
+++ b/src/tree_schema_free.c
@@ -672,6 +672,7 @@
     FREE_STRING(ctx, action->ref);
     FREE_ARRAY(ctx, action->iffeatures, lysc_iffeature_free);
     FREE_ARRAY(ctx, action->exts, lysc_ext_instance_free);
+    FREE_ARRAY(ctx, action->when, lysc_when_free);
     FREE_ARRAY(ctx, action->input_exts, lysc_ext_instance_free);
     lysc_action_inout_free(ctx, &action->input);
     FREE_ARRAY(ctx, action->output_exts, lysc_ext_instance_free);
@@ -688,6 +689,7 @@
     FREE_STRING(ctx, notif->ref);
     FREE_ARRAY(ctx, notif->iffeatures, lysc_iffeature_free);
     FREE_ARRAY(ctx, notif->exts, lysc_ext_instance_free);
+    FREE_ARRAY(ctx, notif->when, lysc_when_free);
     FREE_ARRAY(ctx, notif->musts, lysc_must_free);
     LY_LIST_FOR_SAFE(notif->data, child_next, child) {
         lysc_node_free(ctx, child);