Btrfs: Back port to 2.6.18-el kernels

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index b732391..7cab680 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -35,6 +35,7 @@
 #include <linux/compat.h>
 #include <linux/parser.h>
 #include <linux/ctype.h>
+#include <linux/namei.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"