ProcessCore: Ignore elapsedTime < 0 when updating process usage
QElapsedTimer::restart() of a timer that was not yet started will potentially return something < 0. Since time travel is not possible we can treat it as an invalid value and ignore it.
QElapsedTimer::restart() of a timer that was not yet started will potentially return something < 0. Since time travel is not possible we can treat it as an invalid value and ignore it.