cli/command: don't use legacy "notfound" error-type in tests

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/container/create_test.go

@@ -350,5 +350,5 @@ func TestCreateContainerWithProxyConfig(t *testing.T) {
 
 type fakeNotFound struct{}
 
-func (f fakeNotFound) NotFound() bool { return true }
-func (f fakeNotFound) Error() string  { return "error fake not found" }
+func (f fakeNotFound) NotFound()     {}
+func (f fakeNotFound) Error() string { return "error fake not found" }

cli/command/image/remove_test.go

@@ -21,9 +21,7 @@ func (n notFound) Error() string {
 	return fmt.Sprintf("Error: No such image: %s", n.imageID)
 }
 
-func (n notFound) NotFound() bool {
-	return true
-}
+func (n notFound) NotFound() {}
 
 func TestNewRemoveCommandAlias(t *testing.T) {
 	cmd := newRemoveCommand(test.NewFakeCli(&fakeClient{}))

cli/command/stack/swarm/deploy_composefile_test.go

@@ -14,9 +14,7 @@ type notFound struct {
 	error
 }
 
-func (n notFound) NotFound() bool {
-	return true
-}
+func (n notFound) NotFound() {}
 
 func TestValidateExternalNetworks(t *testing.T) {
 	testcases := []struct {