lists: add "const" qualifier to first arg of list_splice() operations

Since neither the list_splice() nor __list_splice() routines modify their
first argument, might as well declare them "const".

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/list.h

@@ -328,7 +328,7 @@ static inline int list_is_singular(const struct list_head *head)
 	return !list_empty(head) && (head->next == head->prev);
 }
 
-static inline void __list_splice(struct list_head *list,
+static inline void __list_splice(const struct list_head *list,
 				 struct list_head *head)
 {
 	struct list_head *first = list->next;
@@ -347,7 +347,8 @@ static inline void __list_splice(struct list_head *list,
  * @list: the new list to add.
  * @head: the place to add it in the first list.
  */
-static inline void list_splice(struct list_head *list, struct list_head *head)
+static inline void list_splice(const struct list_head *list,
+				struct list_head *head)
 {
 	if (!list_empty(list))
 		__list_splice(list, head);