message: Update 'import-onednn.sh' test case per code review
diff: # limitations under the License.
  # ============================================================================
  -{ # try
  - echo `python -c 'from tensorflow.python import _pywrap_util_port; print(_pywrap_util_port.IsMklEnabled())'`
  +python -c 'from tensorflow.python import _pywrap_util_port; print(_pywrap_util_port.IsMklEnabled())'
  +new_mkl_enabled=$?
  +
  +python -c 'from tensorflow.python import pywrap_tensorflow; print(pywrap_tensorflow.IsMklEnabled())'
  +old_mkl_enabled=$?
  +
  +if [[ $new_mkl_enabled -eq 0 ]]; then
  echo "PASS: MKL is enabled"
  -} || { # catch
  - echo `python -c 'from tensorflow.python import pywrap_tensorflow; print(pywrap_tensorflow.IsMklEnabled())'`
  +elif [[ $old_mkl_enabled -eq 0]]; then
  echo "PASS: Old MKL is detected"
  -} || { # finally
  +else
  die "FAIL: MKL is not enabled"
  -}
  +fi
  