ieee802154: fix one possible memleak in ca8210_dev_com_init

We should call destroy_workqueue to destroy mlme_workqueue in error branch.

Fixes: ded845a7 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Link: https://lore.kernel.org/r/20200720143315.40523-1-liujian56@huawei.comSigned-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

drivers/net/ieee802154/ca8210.c

@@ -2925,6 +2925,7 @@ static int ca8210_dev_com_init(struct ca8210_priv *priv)
 	);
 	if (!priv->irq_workqueue) {
 		dev_crit(&priv->spi->dev, "alloc of irq_workqueue failed!\n");
+		destroy_workqueue(priv->mlme_workqueue);
 		return -ENOMEM;
 	}