Added function to delete contents of AVL tree

include/avltree.h

@@ -39,3 +39,11 @@ struct avltree_t *avl_remove(struct avltree_t *tree, int key);
  * @return void* 
  */
 void *avl_get(struct avltree_t *tree, int key);
+
+/**
+ * @brief Removes every node present on the given tree.
+ * 
+ * @param tree
+ * @return NULL
+ */
+void *avl_clear(struct avltree_t *tree);

src/avltree.c

@@ -199,3 +199,12 @@ void *avl_get(struct avltree_t *tree, int key)
     }
     return NULL;
 }
+
+void *avl_clear(struct avltree_t *tree)
+{
+    while(tree != NULL)
+    {
+        tree = avl_remove(tree, tree->key);
+    }
+    return tree;
+}