To prevent constituents from viewing the survey results, you'll need to set the reporting to Administrator Only by following these steps:
  1. Navigate to Content, Surveys
  2. Edit the survey in question
  3. On page 1. Identify Survey, go to Step 4. Results Security Category
  4. Select Administrators Only from the drop-down list
  5. Click Save

Your report results link will now be removed from the survey and only visible for administrators through the Download Survey Results link.