more trivial ->iterate_shared conversions

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/exofs/dir.c b/fs/exofs/dir.c
index a7661aa..f69a1b5 100644
--- a/fs/exofs/dir.c
+++ b/fs/exofs/dir.c
@@ -657,5 +657,5 @@
 const struct file_operations exofs_dir_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
-	.iterate	= exofs_readdir,
+	.iterate_shared	= exofs_readdir,
 };