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_trusted.c b/fs/ext2/xattr_trusted.c
index 2989467..7e19257 100644
--- a/fs/ext2/xattr_trusted.c
+++ b/fs/ext2/xattr_trusted.c
@@ -5,10 +5,7 @@
  * Copyright (C) 2003 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
  */
 
-#include <linux/string.h>
-#include <linux/capability.h>
-#include <linux/fs.h>
-#include <linux/ext2_fs.h>
+#include "ext2.h"
 #include "xattr.h"
 
 static size_t