fix unit tests broken in 5cb3c10289f79238a04b777143eed8ab970a6177

After fetching 5cb3c10289f79238a04b777143eed8ab970a6177, I suffered failures in unit tests for pkg/registry/service/rest_test.go.  

# github.com/GoogleCloudPlatform/kubernetes/pkg/registry/service
src/github.com/GoogleCloudPlatform/kubernetes/pkg/registry/service/rest_test.go:459: invalid type assertion: created_svc3.(*api.Service) (non-interface type apiserver.RESTResult on left)
src/github.com/GoogleCloudPlatform/kubernetes/pkg/registry/service/rest_test.go:553: invalid type assertion: result.(*api.Status) (non-interface type apiserver.RESTResult on left)
FAIL	github.com/GoogleCloudPlatform/kubernetes/pkg/registry/service [build failed]

This eliminates those errors.

@smarterclayton looks like 5cb3c10289f79238a04b777143eed8ab970a6177 was yours can review?