ceph: build cleanly without CONFIG_DEBUG_FS

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 06b62c02..8aa1ffb 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -112,9 +112,11 @@
  */
 struct ceph_client {
 	__s64 whoami;                   /* my client number */
+#ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs_monmap;
 	struct dentry *debugfs_mdsmap, *debugfs_osdmap;
 	struct dentry *debugfs_dir, *debugfs_dentry_lru, *debugfs_caps;
+#endif
 
 	struct mutex mount_mutex;       /* serialize mount attempts */
 	struct ceph_mount_args *mount_args;