reduce parameters for func JoinOptionPriority

[fanjiyun]

func JoinOptionPriority(ep Endpoint, prio int) EndpointOption {
	return func(ep *endpoint) {
		// ep lock already acquired
		c := ep.network.getController()
		c.Lock()
		sb, ok := c.sandboxes[ep.sandboxID]
		c.Unlock()
		if !ok {
			logrus.Errorf("Could not set endpoint priority value during Join to endpoint %s: No sandbox id present in endpoint", ep.id)
			return
		}
		sb.epPriority[ep.id] = prio
	}
}

maybe we don't need this parameters ep Endpoint ? I made some changes for this.

Relevant PRs:
moby/moby#40974 (open)
docker/cli#2529(open)

Signed-off-by: fanjiyun fan.jiyun@zte.com.cn

[fanjiyun]

@thaJeztah PLAT, thanks.

[thaJeztah]

LGTM, thanks!