ceph: clean up header guards

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/ceph_frag.h b/fs/ceph/ceph_frag.h
index 793f50c..5babb8e 100644
--- a/fs/ceph/ceph_frag.h
+++ b/fs/ceph/ceph_frag.h
@@ -1,5 +1,5 @@
-#ifndef _FS_CEPH_FRAG_H
-#define _FS_CEPH_FRAG_H
+#ifndef FS_CEPH_FRAG_H
+#define FS_CEPH_FRAG_H
 
 /*
  * "Frags" are a way to describe a subset of a 32-bit number space,