virsh: fix vcpupin info
    
    The "virDomainGetInfo" will get for running domain only live info and for
    offline domain only config info. There was no way how to get config info
    for running domain. We will use "vshCPUCountCollect" instead to get the
    correct cpu count that we need to pass to "virDomainGetVcpuPinInfo".
    
    Also cleanup some unnecessary variables and checks that are done by
    drivers.
    
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1160559
    
    Signed-off-by: Pavel Hrdina <phrdina@redhat.com>