Refactor, normalize system load using separate function.
Refactor, normalize system load using separate function.

Cache number of CPU cores, extremely unlikely to change at runtime for
our intended usecases.

Signed-off-by: Joachim Nilsson <583c295fd7602c168ad814279bbc3894ba65f5d6@gmail.com>

troglobit/watchdogd,troglobit/watchdogd