Revert "Update authz plugin list on failure."

This reverts commit fae904af02a184833d2cd5ce9fdd61a4083707c7.

Signed-off-by: Riyaz Faizullabhoy <riyaz.faizullabhoy@docker.com>
Upstream-commit: a64fc8eea3266968c8e0082dbe6a2f5a8a5bbdc0
Component: engine

components/engine/pkg/authorization/plugin.go

@@ -1,20 +1,12 @@
 package authorization
 
 import (
-	"errors"
 	"sync"
 
 	"github.com/docker/docker/pkg/plugingetter"
 	"github.com/docker/docker/pkg/plugins"
 )
 
-var (
-	// ErrInvalidPlugin indicates that the plugin cannot be used. This is
-	// because the plugin was not found or does not implement necessary
-	// functionality
-	ErrInvalidPlugin = errors.New("invalid plugin")
-)
-
 // Plugin allows third party plugins to authorize requests and responses
 // in the context of docker API
 type Plugin interface {
@@ -110,7 +102,7 @@ func (a *authorizationPlugin) initPlugin() error {
 				plugin, e = plugins.Get(a.name, AuthZApiImplements)
 			}
 			if e != nil {
-				err = ErrInvalidPlugin
+				err = e
 				return
 			}
 			a.plugin = plugin.Client()