Fix bogomips calculation

[trasz]

Summary

Fix bogomips calculation. Previously it was off by half.

[trasz]

Meh.

[emaste]

Would be good to put some reference to determining the appropriate bogomips value, either as a comment in the code if there's something reasonable you can link to, or in the commit message if you just found this case by observation (e.g., something like "on the same hardware I noticed that Linux's real bogomips value was twice that that we reported" if that's the case).

[trasz]

It was compared under VMWare Fusion - with the change the value matches what the actual CentOS reports.

[trasz]

Another observation: on my T420 it reports 2491.96, whereas a googled cpuinfo from a real T420 (https://lkml.org/lkml/2011/11/29/116) reports 5182.63.

[emaste]

IMO go ahead and commit, but add a comment referencing your empirical results above