At some point a stray ';' got added into an autotest in a section
of code that is heavily copy pasted. So in turn nearly all the autotests
have this stray ';' after list_devices (and a few in other places).
Make the HostapdCLI class non-static so that each objects corresponds
to a hostapd instance on one network interface (this is independent of
whether the AP instances use one or separate hostapd processes)
