am c059bd42: Skip bad kHz values, and display them accurately

                // get the absolute value of CPU clock frequency in kHz

                int cpuNum = sched_getcpu();

                uint32_t kHz = tcu.getCpukHz(cpuNum);

                kHz = (kHz & ~0xF) | (cpuNum & 0xF);

                kHz = (kHz << 4) | (cpuNum & 0xF);

                // save values in FIFO queues for dumpsys

                // these stores #1, #2, #3 are not atomic with respect to each other,

                // or with respect to store #4 below

        uint32_t sampleLoadNs = mLoadNs[i];

        uint32_t sampleCpukHz = mCpukHz[i];

        loadNs.sample(sampleLoadNs);

        kHz.sample(sampleCpukHz & ~0xF);

        // skip bad kHz samples

        if ((sampleCpukHz & ~0xF) != 0) {

            kHz.sample(sampleCpukHz >> 4);

            if (sampleCpukHz == previousCpukHz) {

            double megacycles = (double) sampleLoadNs * (double) sampleCpukHz * 1e-12;

                double megacycles = (double) sampleLoadNs * (double) (sampleCpukHz >> 4) * 1e-12;

                double adjMHz = megacycles / mixPeriodSec;  // _not_ wallNs * 1e9

                loadMHz.sample(adjMHz);

            }

        }

        previousCpukHz = sampleCpukHz;

    }

    fdprintf(fd, "Simple moving statistics over last %.1f seconds:\n", wall.n() * mixPeriodSec);