memcg: kill dead prev_priority stubs

This code was removed in 25edde0 ("vmscan: kill prev_priority
completely")

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/memcontrol.h

@@ -299,21 +299,6 @@ static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
 {
 }
 
-static inline int mem_cgroup_get_reclaim_priority(struct mem_cgroup *memcg)
-{
-	return 0;
-}
-
-static inline void mem_cgroup_note_reclaim_priority(struct mem_cgroup *memcg,
-						int priority)
-{
-}
-
-static inline void mem_cgroup_record_reclaim_priority(struct mem_cgroup *memcg,
-						int priority)
-{
-}
-
 static inline bool mem_cgroup_disabled(void)
 {
 	return true;