switch usage directly to errdefs.(ErrAlreadyExists and ErrNotFound)

Signed-off-by: Zou Nengren <zouyee1989@gmail.com>

pkg/cri/server/image_status.go

@@ -19,14 +19,14 @@ package server
 import (
 	"encoding/json"
 
+	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/log"
+	imagestore "github.com/containerd/containerd/pkg/cri/store/image"
+
 	imagespec "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 	runtime "k8s.io/cri-api/pkg/apis/runtime/v1"
-
-	"github.com/containerd/containerd/pkg/cri/store"
-	imagestore "github.com/containerd/containerd/pkg/cri/store/image"
 )
 
 // ImageStatus returns the status of the image, returns nil if the image isn't present.
@@ -35,7 +35,7 @@ import (
 func (c *criService) ImageStatus(ctx context.Context, r *runtime.ImageStatusRequest) (*runtime.ImageStatusResponse, error) {
 	image, err := c.localResolve(r.GetImage().GetImage())
 	if err != nil {
-		if err == store.ErrNotExist {
+		if errdefs.IsNotFound(err) {
 			// return empty without error when image not found.
 			return &runtime.ImageStatusResponse{}, nil
 		}