Removal of TEST_IMAGE_NAMESPACE

We don't need the test image namespace anymore since we've already
upgrade those images to the latest multi-arch ones.

Signed-off-by: Dennis Chen <dennis.chen@arm.com>
Upstream-commit: 662bdb4a5638e56d78e66bb2cb5d7a4a751135c9
Component: engine

components/engine/integration-cli/fixtures/load/frozen.go

@@ -26,7 +26,6 @@ const frozenImgDir = "/docker-frozen-images"
 // images were passed in. If the images need to be downloaded, then it will respect
 // the passed in images
 func FrozenImagesLinux(client client.APIClient, images ...string) error {
-	imgNS := os.Getenv("TEST_IMAGE_NAMESPACE")
 	var loadImages []struct{ srcName, destName string }
 	for _, img := range images {
 		if !imageExists(client, img) {
@@ -38,9 +37,6 @@ func FrozenImagesLinux(client client.APIClient, images ...string) error {
 			if img == "hello-world:frozen" {
 				srcName = "hello-world:latest"
 			}
-			if imgNS != "" {
-				srcName = imgNS + "/" + srcName
-			}
 			loadImages = append(loadImages, struct{ srcName, destName string }{
 				srcName:  srcName,
 				destName: img,