Change killing VMs with SIGKILL to proper shutdown. Change-Id: I3547f1b57e33dc5ecd7613d7600e9feeadd44283 Signed-off-by: Karol Latecki <karol.latecki@intel.com> Reviewed-on: https://review.gerrithub.io/366087 Tested-by: SPDK Automated Test System <sys_sgsw@intel.com> Reviewed-by: Jim Harris <james.r.harris@intel.com> Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>