TDA4VM: Calculate A72 cpu load

Hello,

I have a problem with an error in calculating the A72 cpu;  

raw code, I don't understand why use '+=' ?

I think it is more appropriate to use '='

I

utils/perf_stats/src/app_perf_stats_linux.c

void appPerfStatsCpuLoadCalc()
{
   ...
    obj->cpuLoad.total_time   += total_time;
    obj->cpuLoad.busy_time    += (total_time - (diff_cnt[3] + diff_cnt[4]));
   ...
}