simple local filesystems: switch to ->iterate_shared()

no changes needed (XFS isn't simple, but it has the same parallelism
in the interesting parts exercised from CXFS).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index f0f4363..19efd11 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -716,7 +716,7 @@
 const struct file_operations ext2_dir_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
-	.iterate	= ext2_readdir,
+	.iterate_shared	= ext2_readdir,
 	.unlocked_ioctl = ext2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext2_compat_ioctl,