[PATCH v2] ubi: gluebi: Fix NULL pointer dereference caused by ftl notifier

[ZhaoLong Wang]

> 
> IOW, no mtdblock (hence, also no FTLs) on top of gluebi.
> 
> What do you guys think?
> 
> Thanks,
> //richard
> 


JFFS2 needs to work on the block device, so the mtdblock needs to work
on the top of gluebi.

This is directly reflected in the jffs2 mount command, such as

  # mount -t jffs2 /dev/mtdblockX /mnt/jffs2