net: stmmac: remove unnecessary stmmac_mac_set() in stmmac_release()

stmmac_release() calls phylink_stop() and then goes on to call
stmmac_mac_set(, false). However, phylink_stop() will call
stmmac_mac_link_down() before returning, which will do this work.
Remove this unnecessary call.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Furong Xu <0x1207@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1trcI6-005rn8-GV@rmk-PC.armlinux.org.uk
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Russell King (Oracle)

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -4129,9 +4129,6 @@ static int stmmac_release(struct net_device *dev)
 	/* Release and free the Rx/Tx resources */
 	free_dma_desc_resources(priv, &priv->dma_conf);
 
-	/* Disable the MAC Rx/Tx */
-	stmmac_mac_set(priv, priv->ioaddr, false);
-
 	/* Powerdown Serdes if there is */
 	if (priv->plat->serdes_powerdown)
 		priv->plat->serdes_powerdown(dev, priv->plat->bsp_priv);