net: axienet: add missing blank line after declaration

Add missing blank line after declaration. Fixes below
checkpatch warnings.

WARNING: Missing a blank line after declarations
+       struct sockaddr *addr = p;
+       axienet_set_mac_address(ndev, addr->sa_data);

WARNING: Missing a blank line after declarations
+       struct axienet_local *lp = netdev_priv(ndev);
+       disable_irq(lp->tx_irq);

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>