Description: libgtop return zero values on read and write function


Additional info:
* package version(s)
* config and/or log files etc.
libgtop 2.28.4-1

Steps to reproduce:
gjs:
const GTop = imports.gi.GTop;

gdisk = new GTop.glibtop_fsusage();

mount = '/'
GTop.glibtop_get_fsusage(gdisk, mount);

let blocks = gdisk.block_size;

print(blocks);

print('usage1');
print(gdisk.blocks);
print(gdisk.bfree);
print(gdisk.bavail);
print(gdisk.read);
print(gdisk.write);

sleep(5000);

GTop.glibtop_get_fsusage(gdisk, mount);
print('usage2');
print(gdisk.read);
print(gdisk.write);


function sleep(milliseconds) {
var start = new Date().getTime();
for (var i = 0; i < 1e7; i++) {
if ((new Date().getTime() - start) > milliseconds){
break;
}
}
}