ceph: move AES iv definition to shared header

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/ceph_fs.h b/fs/ceph/ceph_fs.h
index bf7dea6..5bf4ec2 100644
--- a/fs/ceph/ceph_fs.h
+++ b/fs/ceph/ceph_fs.h
@@ -74,6 +74,8 @@
 #define CEPH_CRYPTO_NONE 0x0
 #define CEPH_CRYPTO_AES  0x1
 
+#define CEPH_AES_IV "cephsageyudagreg"
+
 /* security/authentication protocols */
 #define CEPH_AUTH_UNKNOWN	0x0
 #define CEPH_AUTH_NONE	 	0x1
diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c
index c931827..a3e627f 100644
--- a/fs/ceph/crypto.c
+++ b/fs/ceph/crypto.c
@@ -75,7 +75,7 @@
 	return crypto_alloc_blkcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
 }
 
-static const u8 *aes_iv = "cephsageyudagreg";
+static const u8 *aes_iv = (u8 *)CEPH_AES_IV;
 
 static int ceph_aes_encrypt(const void *key, int key_len,
 			    void *dst, size_t *dst_len,