list: Adopt list_next_entry() from the Linux kernel

We'll use it to traverse the list of opaque btf_encoder entries in
pahole.

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: acmel

list.h

@@ -289,6 +289,14 @@ static inline void list_splice_init(struct list_head *list,
 #define list_first_entry(ptr, type, member) \
 	list_entry((ptr)->next, type, member)
 
+/**
+ * list_next_entry - get the next element in list
+ * @pos:	the type * to cursor
+ * @member:	the name of the list_head within the struct.
+ */
+#define list_next_entry(pos, member) \
+	list_entry((pos)->member.next, typeof(*(pos)), member)
+
 /**
  * list_for_each	-	iterate over a list
  * @pos:	the &struct list_head to use as a loop cursor.