[errors] Greatly simplify common/errors package.

deploytool/api/deploy/util.go

 // Copyright 2016 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package deploy
 
 import (
         "fmt"
         "strings"
         "time"
@@ skipping 138 matching lines @@
 // If the direction value is not recognized, an error will be returned.
 func IndexDirectionFromAppYAMLString(v string) (AppEngineResources_Index_Direction, error) {
         switch v {
         case "asc", "":
                 return AppEngineResources_Index_ASCENDING, nil
 
         case "desc":
                 return AppEngineResources_Index_DESCENDING, nil
 
         default:
-                return 0, errors.Reason("invalid index direction %(value)q").D("value", v).Err()
+                return 0, errors.Reason("invalid index direction %q", v).Err()
         }
 }
 
 // KubeString returns the Kubernetes "restartPolicy" field string for the
 // enumeration value.
 func (v KubernetesPod_RestartPolicy) KubeString() string {
         switch v {
         case KubernetesPod_RESTART_ALWAYS:
                 return "Always"
         case KubernetesPod_RESTART_ON_FAILURE:
@@ skipping 35 matching lines @@
                 return "Ti"
         case KubernetesPod_Container_Resources_PEBIBYTE:
                 return "Pi"
         case KubernetesPod_Container_Resources_EXBIBYTE:
                 return "Ei"
 
         default:
                 panic(fmt.Errorf("unknown resource unit (%v)", v))
         }
 }