ipmi0: incorrect critical max

[Stephen Borrill <netbsd%precedence.co.uk@localhost>]

On an HP Microserver Gen10 Plus, I found that soon after booting, I get 
the following alert:

ipmi0: critical over limit on '11-LOM-CORE'

If powerd is running (the default), it shuts the machine down (so 
basically as soon as it hits multi-user).

envstat shows that CritMax is zero:

                      Current  CritMax  WarnMax  WarnMin  CritMin  Unit
[ipmi0]
       11-LOM-CORE:    59.253    0.000  110.471                    degC

Seen on 9.3_STABLE, but also in 10 BETA.

I suppose one simple fix would be to ensure that if CritMax is lower 
than WarnMax, it should be set to the value of WarnMax.

Any other things to look at? The machine won't be put into production for 
a few days, so it's good time to experiment

I have put the latest BIOS on the machine

--
Stephen