verify: Get backend using simple api
verify: Get backend using simple api

Make the code simple and clear.

Signed-off-by: SimFG <c74639a19b067d9e85edba8ec789ca81abbc170b@qq.com>

ajityagaty/etcd,mqliang/etcd,etcd-io/etcd,ajityagaty/etcd,ajityagaty/etcd,mqliang/etcd,etcd-io/etcd,etcd-io/etcd,mqliang/etcd