Divide-by-zero in pmcollectl - test failure

[Nathan Scott <nathans@xxxxxxxxxx>]

Hey Stan,

Test 709 hit a div-by-zero python traceback today for me.
I've never seen this one before, but looks like there's an
assumption that network.interface.out.packets rate is never
zero over an interval maybe?

-bash-4.1$ diff 709.out*
29a30,37
> Traceback (most recent call last):
>   File "/usr/bin/pmcollectl", line 692, in <module>
>     ssx.print_line()
>   File "/usr/bin/pmcollectl", line 131, in print_line
>     self.print_verbose()
>   File "/usr/bin/pmcollectl", line 462, in print_verbose
>     sum(self.ss.get_metric_value('network.interface.out.packets')),
> ZeroDivisionError: long division or modulo by zero
33d40
< 9 9 9 9 9 9 9 9 9 9 9

cheers.

--
Nathan