With previous version of patch info about need of erasing blocks was
stored once per boot. It was breaking in following scenario:
1) First boot after installation (erasing blocks after 0xdeadc0de)
2) Doing sysupgrade (with ubidetach & ubiformat)
3) Attaching UBI again (it caused all blocks to be erased)
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@45387 3c298f89-4303-0410-b956-a3cf2f4a3e73