[XFRM]: Convert XFRM_MSG_* macros to an enum.

This way we will not forget to update XFRM_MSG_MAX in
the future.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@redhat.com>

include/linux/xfrm.h

@@ -103,26 +103,40 @@ enum
 };
 
 /* Netlink configuration messages.  */
-#define XFRM_MSG_BASE		0x10
-
-#define XFRM_MSG_NEWSA		(XFRM_MSG_BASE + 0)
-#define XFRM_MSG_DELSA		(XFRM_MSG_BASE + 1)
-#define XFRM_MSG_GETSA		(XFRM_MSG_BASE + 2)
-
-#define XFRM_MSG_NEWPOLICY	(XFRM_MSG_BASE + 3)
-#define XFRM_MSG_DELPOLICY	(XFRM_MSG_BASE + 4)
-#define XFRM_MSG_GETPOLICY	(XFRM_MSG_BASE + 5)
-
-#define XFRM_MSG_ALLOCSPI	(XFRM_MSG_BASE + 6)
-#define XFRM_MSG_ACQUIRE	(XFRM_MSG_BASE + 7)
-#define XFRM_MSG_EXPIRE		(XFRM_MSG_BASE + 8)
-
-#define XFRM_MSG_UPDPOLICY	(XFRM_MSG_BASE + 9)
-#define XFRM_MSG_UPDSA		(XFRM_MSG_BASE + 10)
-
-#define XFRM_MSG_POLEXPIRE	(XFRM_MSG_BASE + 11)
-
-#define XFRM_MSG_MAX		(XFRM_MSG_POLEXPIRE+1)
+enum {
+	XFRM_MSG_BASE = 0x10,
+
+	XFRM_MSG_NEWSA = 0x10,
+#define XFRM_MSG_NEWSA XFRM_MSG_NEWSA
+	XFRM_MSG_DELSA,
+#define XFRM_MSG_DELSA XFRM_MSG_DELSA
+	XFRM_MSG_GETSA,
+#define XFRM_MSG_GETSA XFRM_MSG_GETSA
+
+	XFRM_MSG_NEWPOLICY,
+#define XFRM_MSG_NEWPOLICY XFRM_MSG_NEWPOLICY
+	XFRM_MSG_DELPOLICY,
+#define XFRM_MSG_DELPOLICY XFRM_MSG_DELPOLICY
+	XFRM_MSG_GETPOLICY,
+#define XFRM_MSG_GETPOLICY XFRM_MSG_GETPOLICY
+
+	XFRM_MSG_ALLOCSPI,
+#define XFRM_MSG_ALLOCSPI XFRM_MSG_ALLOCSPI
+	XFRM_MSG_ACQUIRE,
+#define XFRM_MSG_ACQUIRE XFRM_MSG_ACQUIRE
+	XFRM_MSG_EXPIRE,
+#define XFRM_MSG_EXPIRE XFRM_MSG_EXPIRE
+
+	XFRM_MSG_UPDPOLICY,
+#define XFRM_MSG_UPDPOLICY XFRM_MSG_UPDPOLICY
+	XFRM_MSG_UPDSA,
+#define XFRM_MSG_UPDSA XFRM_MSG_UPDSA
+
+	XFRM_MSG_POLEXPIRE,
+#define XFRM_MSG_POLEXPIRE XFRM_MSG_POLEXPIRE
+
+	XFRM_MSG_MAX
+};
 
 struct xfrm_user_tmpl {
 	struct xfrm_id		id;