net: ethernet: ti: cpsw: drop unused var poll from cpsw_update_channels_res

static int cpsw_update_channels_res(struct cpsw_priv *priv, int ch_num, int rx)

{

	int (*poll)(struct napi_struct *, int);

	struct cpsw_common *cpsw = priv->cpsw;

	void (*handler)(void *, int, int);

	struct netdev_queue *queue;

		ch = &cpsw->rx_ch_num;

		vec = cpsw->rxv;

		handler = cpsw_rx_handler;

		poll = cpsw_rx_poll;

	} else {

		ch = &cpsw->tx_ch_num;

		vec = cpsw->txv;

		handler = cpsw_tx_handler;

		poll = cpsw_tx_poll;

	}

	while (*ch < ch_num) {