[docs] fix paramater name to disable locking for S3 backend (#14911)

website/source/docs/backends/types/s3.html.md

@@ -13,7 +13,8 @@ description: |-
 Stores the state as a given key in a given bucket on
 [Amazon S3](https://aws.amazon.com/s3/).
 This backend also supports state locking via
-[Dynamo DB](https://aws.amazon.com/dynamodb/).
+[Dynamo DB](https://aws.amazon.com/dynamodb/). Enable locking by setting the
+`lock_table` key to a Dynamo DB table to use for the locks.
 
 ~> **Warning!** It is highly recommended that you enable
 [Bucket Versioning](http://docs.aws.amazon.com/AmazonS3/latest/UG/enable-bucket-versioning.html)
@@ -93,7 +94,8 @@ The following configuration options or environment variables are supported:
  * `kms_key_id` - (Optional) The ARN of a KMS Key to use for encrypting
    the state.
  * `lock_table` - (Optional) The name of a DynamoDB table to use for state
-   locking. The table must have a primary key named LockID.
+   locking. The table must have a primary key named LockID. If not present,
+   locking will be disabled.
  * `profile` - (Optional) This is the AWS profile name as set in the
    shared credentials file.
  * `shared_credentials_file`  - (Optional) This is the path to the

website/source/upgrade-guides/0-9.html.markdown

@@ -62,8 +62,8 @@ use these backends, you can ignore this section.
 Specific notes for each affected backend:
 
   * **Amazon S3**: DynamoDB is used for locking. The AWS access keys
-    must have access to Dynamo. You may disable locking by specifying
-	`lock = false` in your backend configuration.
+    must have access to Dynamo. You may disable locking by omitting the
+    `lock_table` key in your backend configuration.
 
   * **HashiCorp Consul**: Sessions are used for locking. If an auth token
     is used it must have permissions to create and destroy sessions. You