Fix potential divide-by-zero, can result in "soft bootloop" for some devices

        long sampleTime = mCurrentSampleTime - mLastSampleTime;

        long sampleRealTime = mCurrentSampleRealTime - mLastSampleRealTime;

        if (sampleRealTime > 0) {

            long percAwake = (sampleTime*100) / sampleRealTime;

            if (percAwake != 100) {

                pw.print(" with ");

                pw.print(percAwake);

                pw.print("% awake");

            }

        }

        pw.println(":");

        final int totalTime = mRelUserTime + mRelSystemTime + mRelIoWaitTime