validate files and replace if necessary

It is possible that someone uses the same system on the same removable storage. In this case we need to validate EFS files and replace them if necessary, otherwise it will fail.

Another way to solve this is to read some serial number and store files at a subdirectory like /var/lib/rmtfs/<serial number>

If anyone faces this the workaround is to remove files from /var/lib/rmtfs