missing calloc failure checks in src/lpmd_util.c

[ColinIanKing]

There are two calloc() calls that are not checked for NULL returns, the following memcpy/memset calls will trigger segmentation faults on the null pointers of proc_stat_prev and proc_stat_cur if calloc fails.

static int parse_proc_stat(void)
{
        FILE *filep;
        int i; 
        int val;
        int count = get_max_online_cpu() + 1;
        int sys_idx = count - 1;
        int size = sizeof(struct proc_stat_info) * count;
 
        filep = fopen (PATH_PROC_STAT, "r");
        if (!filep)
                return 1;
 
        if (!proc_stat_prev)
                proc_stat_prev = calloc(sizeof(struct proc_stat_info), count);
        if (!proc_stat_cur)
                proc_stat_cur = calloc(sizeof(struct proc_stat_info), count);

        memcpy (proc_stat_prev, proc_stat_cur, size);
        memset (proc_stat_cur, 0, size);