Fix incorrect paths in presigned URL links

Author: smartandhandsome

javav2/example_code/s3/README.md

@@ -88,8 +88,8 @@ functions within the same service.
 
 
 <!--custom.examples.start-->
-- [Create a presigned URL for download](s3/src/main/java/com/example/s3/GeneratePresignedGetUrlAndRetrieve.java)
-- [Create a presigned URL for upload](s3/src/main/java/com/example/s3/GeneratePresignedUrlAndPutFileWithMetadata.java)
+- [Create a presigned URL for download](src/main/java/com/example/s3/GeneratePresignedGetUrlAndRetrieve.java)
+- [Create a presigned URL for upload](src/main/java/com/example/s3/GeneratePresignedUrlAndPutFileWithMetadata.java)
 <!--custom.examples.end-->
 
 ## Run the examples
@@ -305,4 +305,4 @@ in the `javav2` folder.
 
 Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 
-SPDX-License-Identifier: Apache-2.0
+SPDX-License-Identifier: Apache-2.0