Title: ibm_imm_fan: Fixed crash if fan speed is "unavailable"
Level: 1
Component: checks
Class: fix
Compatible: compat
State: unknown
Version: 1.2.8p16
Date: 1483438073

If the value for speed is "unavailable" the behaviour is now similar to
"offline": The state becomes CRIT and the status detail shows the output "is unvailable".

