cli integration: sync container & image deletion

This makes container and image removal in the tests run synchronously.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)

integration-cli/docker_cli_export_import_test.go

@@ -40,8 +40,8 @@ func TestExportContainerAndImportImage(t *testing.T) {
 	out, _, err = runCommandWithOutput(inspectCmd)
 	errorOut(err, t, fmt.Sprintf("output should've been an image id: %v %v", out, err))
 
-	go deleteImages("testexp")
-	go deleteContainer(cleanedContainerID)
+	deleteContainer(cleanedContainerID)
+	deleteImages("testexp")
 
 	os.Remove("/tmp/testexp.tar")