Move some hardcoded definitions to an enum type.

Signed-off-by: Glauber Costa <redacted>
CC: Kirill A. Shutemov <redacted>
CC: Greg Thelen <redacted>
CC: Johannes Weiner <redacted>
CC: Michal Hocko <redacted>
CC: Hiroyouki Kamezawa <redacted>
CC: Paul Turner <redacted>
CC: Frederic Weisbecker <redacted>
---
 mm/memcontrol.c |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6728a7a..b15a693 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c

@@ -351,9 +351,13 @@ enum charge_type {
 };
 
 /* for encoding cft->private value on file */
-#define _MEM			(0)
-#define _MEMSWAP		(1)
-#define _OOM_TYPE		(2)
+
+enum mem_type {
+	_MEM = 0,
+	_MEMSWAP,
+	_OOM_TYPE,
+};
+
 #define MEMFILE_PRIVATE(x, val)	(((x) << 16) | (val))
 #define MEMFILE_TYPE(val)	(((val) >> 16) & 0xffff)
 #define MEMFILE_ATTR(val)	((val) & 0xffff)

-- 
1.7.7.6