[readdir] switch dcache_readdir() users to ->iterate()

new helpers - dir_emit_dot(file, ctx, dentry), dir_emit_dotdot(file, ctx),
dir_emit_dots(file, ctx).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 085da86..ca8e555 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -41,7 +41,7 @@
 	.open		= dcache_dir_open,
 	.release	= dcache_dir_close,
 	.read		= generic_read_dir,
-	.readdir	= dcache_readdir,
+	.iterate	= dcache_readdir,
 	.llseek		= dcache_dir_lseek,
 	.unlocked_ioctl	= autofs4_root_ioctl,
 #ifdef CONFIG_COMPAT
@@ -53,7 +53,7 @@
 	.open		= autofs4_dir_open,
 	.release	= dcache_dir_close,
 	.read		= generic_read_dir,
-	.readdir	= dcache_readdir,
+	.iterate	= dcache_readdir,
 	.llseek		= dcache_dir_lseek,
 };