defer file close

Author: wing328

modules/openapi-generator/src/main/resources/go/client.mustache

@@ -592,11 +592,7 @@ func addFile(w *multipart.Writer, fieldName, path string) error {
 	if err != nil {
 		return err
 	}
-	err = file.Close()
-
-	if err != nil {
-		return err
-	}
+	defer file.Close()
 
 	part, err := w.CreateFormFile(fieldName, filepath.Base(path))
 	if err != nil {