net:ethernet:aquantia: Remove adapter re-opening when MTU changed.

Closing/opening the adapter is not needed at all.
The new MTU settings take effect immediately.

Fixes: 97bde5c4 ("net: ethernet: aquantia: Support for NIC-specific code")
Signed-off-by: NPavel Belous <pavel.belous@aquantia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/aquantia/atlantic/aq_main.c

@@ -100,11 +100,6 @@ static int aq_ndev_change_mtu(struct net_device *ndev, int new_mtu)
 		goto err_exit;
 	ndev->mtu = new_mtu;
 
-	if (netif_running(ndev)) {
-		aq_ndev_close(ndev);
-		aq_ndev_open(ndev);
-	}
-
 err_exit:
 	return err;
 }