tools/kvm_stat: fix python3 issues

tools/kvm_stat: fix python3 issues

BugLink: https://bugs.launchpad.net/bugs/1798776
Python3 returns a float for a regular division - switch to a division
operator that returns an integer.
Furthermore, filters return a generator object instead of the actual
list - wrap result in yet another list, which makes it still work in
both, Python2 and 3.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
(cherry picked from commit 58f33cfe73076b6497bada4f7b5bda961ed68083)
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Acked-by: Kleber Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>