r/aws_elbv2_trust_store_revocation: fix to properly return create errors

Previously the error was appended to the existing diagnostics but not returned, allowing the create operation to proceed and eventually attempt dereferencing a nil pointer to the create API response.

```console
% make testacc PKG=elbv2 TESTS=TestAccELBV2TrustStoreRevocation_
make: Verifying source code with gofmt...
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go1.22.6 test ./internal/service/elbv2/... -v -count 1 -parallel 20 -run='TestAccELBV2TrustStoreRevocation_'  -timeout 360m

--- PASS: TestAccELBV2TrustStoreRevocation_basic (53.44s)
PASS
ok      github.com/hashicorp/terraform-provider-aws/internal/service/elbv2      59.341s
```

.changelog/38756.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+resource/aws_elbv2_trust_store_revocation: Fix to properly return errors during resource creation
+```

internal/service/elbv2/trust_store_revocation.go

@@ -98,7 +98,7 @@ func resourceTrustStoreRevocationCreate(ctx context.Context, d *schema.ResourceD
 	output, err := conn.AddTrustStoreRevocations(ctx, input)
 
 	if err != nil {
-		sdkdiag.AppendErrorf(diags, "creating ELBv2 Trust Store (%s) Revocation (s3://%s/%s): %s", trustStoreARN, s3Bucket, s3Key, err)
+		return sdkdiag.AppendErrorf(diags, "creating ELBv2 Trust Store (%s) Revocation (s3://%s/%s): %s", trustStoreARN, s3Bucket, s3Key, err)
 	}
 
 	revocationID := aws.ToInt64(output.TrustStoreRevocations[0].RevocationId)