message: add the HipfftError impl when no hipfft
diff: @@ -39,6 +39,14 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  namespace gko {
  +
  +
  +std::string HipfftError::get_error(int64 error_code)
  +{
  + return "Does not contain hipfft.";
  +}
  +
  +
  namespace kernels {
  namespace hip {
  /**
  