nifcloud: fix API requests (go-acme#2039)

Author: ldez

providers/dns/nifcloud/internal/client.go

@@ -149,18 +149,17 @@ func (c *Client) sign(req *http.Request) error {
 }
 
 func newXMLRequest(ctx context.Context, method string, endpoint *url.URL, payload any) (*http.Request, error) {
-	buf := new(bytes.Buffer)
+	body := new(bytes.Buffer)
 
 	if payload != nil {
-		body := new(bytes.Buffer)
 		body.WriteString(xml.Header)
 		err := xml.NewEncoder(body).Encode(payload)
 		if err != nil {
 			return nil, fmt.Errorf("failed to create request XML body: %w", err)
 		}
 	}
 
-	req, err := http.NewRequestWithContext(ctx, method, endpoint.String(), buf)
+	req, err := http.NewRequestWithContext(ctx, method, endpoint.String(), body)
 	if err != nil {
 		return nil, fmt.Errorf("unable to create request: %w", err)
 	}