migrate ext2_fs.h guts to fs/ext2/ext2.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
index be7a8d0..cfedb2c 100644
--- a/fs/ext2/xattr_security.c
+++ b/fs/ext2/xattr_security.c
@@ -3,10 +3,7 @@
  * Handler for storing security labels as extended attributes.
  */
 
-#include <linux/slab.h>
-#include <linux/string.h>
-#include <linux/fs.h>
-#include <linux/ext2_fs.h>
+#include "ext2.h"
 #include <linux/security.h>
 #include "xattr.h"