Fix --ipc=host dependency on /dev/mqueue existing

Since #15862, containers fail to start when started with --ipc=host if
/dev/mqueue is not present. This change causes docker to create
container-local mounts for --ipc=host containers as well as in the
default case.

Signed-off-by: Burke Libbey <burke.libbey@shopify.com>

daemon/container.go

@@ -288,7 +288,7 @@ func (container *Container) Start() (err error) {
 		return err
 	}
 
-	if !container.hostConfig.IpcMode.IsContainer() && !container.hostConfig.IpcMode.IsHost() {
+	if !container.hostConfig.IpcMode.IsContainer() {
 		if err := container.setupIpcDirs(); err != nil {
 			return err
 		}

daemon/container_unix.go

@@ -214,12 +214,6 @@ func populateCommand(c *Container, env []string) error {
 		ipc.ContainerID = ic.ID
 		c.ShmPath = ic.ShmPath
 		c.MqueuePath = ic.MqueuePath
-	} else {
-		ipc.HostIpc = c.hostConfig.IpcMode.IsHost()
-		if ipc.HostIpc {
-			c.ShmPath = "/dev/shm"
-			c.MqueuePath = "/dev/mqueue"
-		}
 	}
 
 	pid := &execdriver.Pid{}
@@ -1408,7 +1402,7 @@ func (container *Container) setupIpcDirs() error {
 }
 
 func (container *Container) unmountIpcMounts() error {
-	if container.hostConfig.IpcMode.IsContainer() || container.hostConfig.IpcMode.IsHost() {
+	if container.hostConfig.IpcMode.IsContainer() {
 		return nil
 	}