resource/aws_volume_attachment: Do not swallow error when detaching volume (#12596)
resource/aws_volume_attachment: Do not swallow error when detaching volume (#12596)

Output from acceptance testing:

```
--- PASS: TestAccAWSVolumeAttachment_update (84.99s)
--- PASS: TestAccAWSVolumeAttachment_basic (99.04s)
--- PASS: TestAccAWSVolumeAttachment_skipDestroy (200.97s)
--- PASS: TestAccAWSVolumeAttachment_attachStopped (226.76s)
```
terraform-providers/terraform-provider-aws,kjmkznr/terraform-provider-aws,terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,terraform-providers/terraform-provider-aws,kjmkznr/terraform-provider-aws