fix sd-ext backup and restore.

Change-Id: I346724f231bb29df2c0fa833df420620ab1be1b4
diff --git a/etc/init.rc b/etc/init.rc
index e6b43e0..611f5b4 100644
--- a/etc/init.rc
+++ b/etc/init.rc
@@ -10,6 +10,8 @@
     symlink /system/etc /etc
 
     mkdir /sdcard
+    mkdir /sd-ext
+    mkdir /datadata
     mkdir /emmc
     mkdir /system
     mkdir /data