add golangci-lint.

server/utility/tree/tree.go

@@ -49,7 +49,6 @@ func GetIds(tree string) (ids []int64) {
 			ids = append(ids, newId)
 		}
 	}
-
 	return
 }
 
@@ -65,7 +64,7 @@ func GenTree(menus []map[string]interface{}) (realMenu []map[string]interface{})
 // GenTreeWithField 生成关系树 自定义生成属性
 func GenTreeWithField(menus []map[string]interface{}, op GenOption) (realMenu []map[string]interface{}) {
 	if len(menus) < 1 {
-		return nil
+		return
 	}
 
 	minPid := GetMinPid(menus, op.PidField)