double increment in the disk check loop

[xmonader]

not sure why is checked loop variable is incremented twice? and not sure how it affects the accuracy

[maxux]

This repository is not maintained, it moved to threefoldtech organization.
This « bug » is not present on latest code update: threefoldtech#3
But this PR was not merged, I'll do review with @muhamadazmy to ensure I can merge it with no issue zos side.

Anyway, there are 128 loops, this double incrementation is indeed not supposed to be there but just reduce the tests to 64 loops, final result is the average. Amount of loops is just there to make average the more accurate possible, that mistake doesn't really make value less accurate :)