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.h b/src/tree_schema.h
index eb0f609..8c72eba 100644
--- a/src/tree_schema.h
+++ b/src/tree_schema.h
@@ -108,7 +108,6 @@
  * - ::lysc_has_when()
  *
  * - ::lysc_node_children()
- * - ::lysc_node_parent_full()
  * - ::lysc_node_actions()
  * - ::lysc_node_notifs()
  *
@@ -213,7 +212,7 @@
     } \
     while (!(LYSC_TREE_DFS_next)) { \
         /* parent is already processed, go to its sibling */ \
-        (ELEM) = (struct lysc_node *)lysc_node_parent_full(ELEM); \
+        (ELEM) = (ELEM)->parent; \
         _LYSC_TREE_DFS_NEXT(START, ELEM, LYSC_TREE_DFS_next); \
     } }
 
@@ -227,7 +226,7 @@
     } \
     if ((ELEM)->nodetype == LYS_INPUT) { \
         /* after input, get output */ \
-        (NEXT) = (struct lysc_node *)lysc_node_children(lysc_node_parent_full(ELEM), LYS_CONFIG_R); \
+        (NEXT) = (struct lysc_node *)lysc_node_children((ELEM)->parent, LYS_CONFIG_R); \
     } else if ((ELEM)->nodetype == LYS_OUTPUT) { \
         /* no sibling of output */ \
         (NEXT) = NULL; \
@@ -1968,17 +1967,6 @@
 const struct lysc_node *lysc_node_children(const struct lysc_node *node, uint16_t flags);
 
 /**
- * @brief Get the parent pointer from any type of (compiled) schema node.
- * Returns input or output for direct descendants of RPC/action nodes.
- * To skip them, use ::lysc_node.parent pointer directly.
- *
- * @param[in] node Node whose parent to get.
- * @return Node parent.
- * @return NULL is there is none.
- */
-const struct lysc_node *lysc_node_parent_full(const struct lysc_node *node);
-
-/**
  * @brief Callback to be called for every schema node in a DFS traversal.
  *
  * @param[in] node Current node.