mm/memcg: clean up obsolete enum charge_type

Patch series "mm/memcg: Miscellaneous cleanups and streamlining", v2.

This patch (of 3):

Since commit 0a31bc9 ("mm: memcontrol: rewrite uncharge API") and
commit 00501b5 ("mm: memcontrol: rewrite charge API") in v3.17, the
enum charge_type was no longer used anywhere.  However, the enum itself
was not removed at that time.  Remove the obsolete enum charge_type now.

Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Chris Down <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Yafang Shao <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

mm/memcontrol.c

@@ -197,14 +197,6 @@ static struct move_charge_struct {
 #define	MEM_CGROUP_MAX_RECLAIM_LOOPS		100
 #define	MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS	2
 
-enum charge_type {
-	MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
-	MEM_CGROUP_CHARGE_TYPE_ANON,
-	MEM_CGROUP_CHARGE_TYPE_SWAPOUT,	/* for accounting swapcache */
-	MEM_CGROUP_CHARGE_TYPE_DROP,	/* a page was unused swap cache */
-	NR_CHARGE_TYPE,
-};
-
 /* for encoding cft->private value on file */
 enum res_type {
 	_MEM,