modify FIPS checks

- we need a way to notify an user about running misconfigured system which
will turn to be unusable in real FIPS mode. For more details look at:
http://bugzilla.redhat.com/show_bug.cgi?id=1009707#c25

- also fixes invisble verbose log about running in FIPS mode due to its misplacement
Print minimal device size if LUKS header space is too small.