test: Revert "test: Fix mockContainer"

This reverts commit ab489ae.
To fix shimv2 tests random fails.

Fixes: kata-containers#502

Signed-off-by: Hui Zhu <teawater@hyper.sh>

mockcontainer.go

@@ -12,7 +12,6 @@ import (
 
 	"github.com/opencontainers/runc/libcontainer"
 	"github.com/opencontainers/runc/libcontainer/configs"
-	"github.com/opencontainers/runtime-spec/specs-go"
 )
 
 type mockContainer struct {
@@ -34,10 +33,6 @@ func (m *mockContainer) State() (*libcontainer.State, error) {
 	return nil, nil
 }
 
-func (m *mockContainer) OCIState() (*specs.State, error) {
-	return nil, nil
-}
-
 func (m *mockContainer) Config() configs.Config {
 	return configs.Config{
 		Capabilities: &configs.Capabilities{},