+/**
+ * list_tail - get the last entry in a list
+ * @h: the list_head
+ * @type: the type of the entry
+ * @member: the list_node member of the type
+ *
+ * If the list is empty, returns NULL.
+ *
+ * Example:
+ * struct child *last;
+ * last = list_tail(&parent->children, struct child, list);
+ */
+#define list_tail(h, type, member) \
+ (list_empty(h) ? NULL : list_entry((h)->n.prev, type, member))