See comments below from Rodrigo for the complete steps :)
You have a survey that you would like people to fill out but not edit or delete responses. The settings are not obvious so here they are…
Go to your survey settings and click Advanced Settings.
Select “All responses” for Read AND Edit access
Click OK to go back to the Survey Settings page
Select “Permissions for this survey”
If the survey inherits permissions, click Actions – Edit Permissions and click OK on the dialog
Give all of the users Contribute rights
That’s it! Easy but not obvious.
This should remove the “Survey Settings” link on the survey page for users.