ceph: clean up header guards

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/ceph_fs.h b/fs/ceph/ceph_fs.h
index 86fadeb..663ff90 100644
--- a/fs/ceph/ceph_fs.h
+++ b/fs/ceph/ceph_fs.h
@@ -9,8 +9,8 @@
  * LGPL2
  */
 
-#ifndef _FS_CEPH_CEPH_FS_H
-#define _FS_CEPH_CEPH_FS_H
+#ifndef CEPH_FS_H
+#define CEPH_FS_H
 
 #include "msgr.h"
 #include "rados.h"