better error detection

[smyers119]

I was spinning up a new instance on a container in my private cloud. Installed efa4 which originally did not complete successfully because i was missing yum-utils. After i installed that everything seemed to go ok. When i went to do a system restore that failed because tar was not installed. The script itself did not catch the failure and continued to run, which i believe may have messed up the passwords.

[shawniverson]

https://github.com/E-F-A/v4/issues/212