[Ltib] mkfs.cramfs can't make 3-level-deep dirs

[Ned Konz]

I have a device table that makes several directories.

In it I have some entries (both directories and devices) that are 3- 
levels deep in the directory structure.

The mkfs.cramfs that was built as part of the LTIB can't handle these:  
it says "could not find parent".

Another version of mkfs.cramfs that I got from the Timesys package did  
not have this problem.