Merge pull request #17458 from LK4D4/unnec_err

Remove unnecessary error returns

daemon/daemon.go

@@ -955,14 +955,12 @@ func (daemon *Daemon) stats(c *Container) (*execdriver.ResourceStats, error) {
 	return daemon.execDriver.Stats(c.ID)
 }
 
-func (daemon *Daemon) subscribeToContainerStats(c *Container) (chan interface{}, error) {
-	ch := daemon.statsCollector.collect(c)
-	return ch, nil
+func (daemon *Daemon) subscribeToContainerStats(c *Container) chan interface{} {
+	return daemon.statsCollector.collect(c)
 }
 
-func (daemon *Daemon) unsubscribeToContainerStats(c *Container, ch chan interface{}) error {
+func (daemon *Daemon) unsubscribeToContainerStats(c *Container, ch chan interface{}) {
 	daemon.statsCollector.unsubscribe(c, ch)
-	return nil
 }
 
 func (daemon *Daemon) changes(container *Container) ([]archive.Change, error) {

daemon/stats.go

@@ -35,11 +35,6 @@ func (daemon *Daemon) ContainerStats(prefixOrName string, config *ContainerStats
 		return json.NewEncoder(config.OutStream).Encode(&types.Stats{})
 	}
 
-	updates, err := daemon.subscribeToContainerStats(container)
-	if err != nil {
-		return err
-	}
-
 	if config.Stream {
 		// Write an empty chunk of data.
 		// This is to ensure that the HTTP status code is sent immediately,
@@ -65,6 +60,7 @@ func (daemon *Daemon) ContainerStats(prefixOrName string, config *ContainerStats
 
 	enc := json.NewEncoder(config.OutStream)
 
+	updates := daemon.subscribeToContainerStats(container)
 	defer daemon.unsubscribeToContainerStats(container, updates)
 
 	noStreamFirstFrame := true