schema CHANGE remove lysc_node_parent_full()
The function is no more neededed after unifying all the schema node
structures available as parents.
diff --git a/src/tree_schema_internal.h b/src/tree_schema_internal.h
index 558c010..afeefac 100644
--- a/src/tree_schema_internal.h
+++ b/src/tree_schema_internal.h
@@ -676,7 +676,7 @@
/**
* @brief Same as ::lysc_data_node() but never returns the node itself.
*/
-#define lysc_data_parent(schema) lysc_data_node(lysc_node_parent_full(schema))
+#define lysc_data_parent(SCHEMA) lysc_data_node((SCHEMA)->parent)
/**
* @brief Learn whether a node is inside an operation output.