Reduce the number of random tests. In previous patch, non-1:1 mapping is enbaled and it may need more than an hour and a half for the CI test, which may lead to CI timeout. Reduce the number of random test count to pass the CI. Signed-off-by: Dun Tan <dun.tan@intel.com> Cc: Eric Dong <eric.dong@intel.com> Reviewed-by: Ray Ni <ray.ni@intel.com> Cc: Rahul Kumar <rahul1.kumar@intel.com> Tested-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com>