Remove some unused structs and fields

Signed-off-by: Alexander Morozov <lk4d4@docker.com>
Upstream-commit: 0a352e1a906fbf7592aa95d6327776236d13392a
Component: engine

components/engine/api/client/events.go

@@ -121,7 +121,6 @@ func printOutput(event eventtypes.Message, output io.Writer) {
 type eventHandler struct {
 	handlers map[string]func(eventtypes.Message)
 	mu       sync.Mutex
-	closed   bool
 }
 
 func (w *eventHandler) Handle(action string, h func(eventtypes.Message)) {

components/engine/daemon/execdriver/native/driver.go

@@ -123,11 +123,6 @@ func NewDriver(root string, options []string) (*Driver, error) {
 	}, nil
 }
 
-type execOutput struct {
-	exitCode int
-	err      error
-}
-
 // Run implements the exec driver Driver interface,
 // it calls libcontainer APIs to run a container.
 func (d *Driver) Run(c *execdriver.Command, pipes *execdriver.Pipes, hooks execdriver.Hooks) (execdriver.ExitStatus, error) {

components/engine/daemon/logger/jsonfilelog/jsonfilelog.go

@@ -25,7 +25,6 @@ type JSONFileLogger struct {
 	buf     *bytes.Buffer
 	writer  *loggerutils.RotateFileWriter
 	mu      sync.Mutex
-	ctx     logger.Context
 	readers map[*logger.LogWatcher]struct{} // stores the active log followers
 	extra   []byte                          // json-encoded extra attributes
 }