add test for virt-xml-validate

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>

virt_xml_validate: fix an spelling error in cfg and provide an interface for other schemas.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Add test for virt-top.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>

virt_top: remove an unused variable.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>