Option -y added to iostat.

Option -y added to iostat.

This option tells iostat to not display its first report with statistics
since system boot.
Courtesy Peter Schiffer from RedHat.

Mail from Peter Schiffer 20/11/2012 (pschiffe@redhat.com):

I want to talk to you about one feature of iostat command. When you ran
iostat without any arguments, it prints statistics since boot. This is
OK, and, for example, mpstat is doing the same. However, when you run
let's say iostat 1 5, the first report displays statistics since boot.
This can be a problem in numerous situations. Well, I am not sure when
this behavior is beneficial and usually this first report is removed by
some kind of post-processing. When compared to mpstat, the first report
is skipped and it waits to the next report. And I think this is the
default behavior for all other sysstat tools.

Now, I was wondering about how to make it better. I don't think that it
would be wise to change default behavior - that could break things.
But I was thinking more about some new option which would make iostat
skip the first since boot report.

What do you think about it?