#7 iperf: Fix "speed" display in CSV report

[Atul Singh MandLA]

There is an issue with the display of speed in CSV report.
Some parameters displayed in the CSV reports are declared as uint64_t, but the printf format doesn't reflect this. I have generated this patch to fix the issue.
Please let me know your feedback.

Thank you.

[Robert McMahon]

Do you think the I64d should also be changed to use PRId64?

Bib

[Matt Weber]

I believe I64d says print 64 spaces ahead of your %d, PRId64 says cast to 64-bit for this architecture. So I think it's ok