image_pull: fix image resolver

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

server/image_remove.go

@@ -2,9 +2,9 @@ package server
 
 import (
 	"fmt"
-	"strings"
 	"time"
 
+	"github.com/kubernetes-incubator/cri-o/pkg/storage"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
 	pb "k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
@@ -33,8 +33,7 @@ func (s *Server) RemoveImage(ctx context.Context, req *pb.RemoveImageRequest) (r
 	)
 	images, err = s.StorageImageServer().ResolveNames(image)
 	if err != nil {
-		// This means we got an image ID
-		if strings.Contains(err.Error(), "cannot specify 64-byte hexadecimal strings") {
+		if err == storage.ErrCannotParseImageID {
 			images = append(images, image)
 		} else {
 			return nil, err