vfio/container: Make vfio_connect_container() return bool This is to follow the coding standand to return bool if 'Error **' is used to pass error. Suggested-by: Cédric Le Goater <clg@redhat.com> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Reviewed-by: Cédric Le Goater <clg@redhat.com> Signed-off-by: Cédric Le Goater <clg@redhat.com>