bonding: simple code refactor

Remove duplicate code.
Signed-off-by: NMahesh Bandewar <maheshb@google.com>
Signed-off-by: NAndy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -2900,6 +2900,8 @@ static int bond_slave_netdev_event(unsigned long event,
 			if (old_duplex != slave->duplex)
 				bond_3ad_adapter_duplex_changed(slave);
 		}
+		/* Fallthrough */
+	case NETDEV_DOWN:
 		/* Refresh slave-array if applicable!
 		 * If the setup does not use miimon or arpmon (mode-specific!),
 		 * then these events will not cause the slave-array to be
@@ -2911,10 +2913,6 @@ static int bond_slave_netdev_event(unsigned long event,
 		if (bond_mode_uses_xmit_hash(bond))
 			bond_update_slave_arr(bond, NULL);
 		break;
-	case NETDEV_DOWN:
-		if (bond_mode_uses_xmit_hash(bond))
-			bond_update_slave_arr(bond, NULL);
-		break;
 	case NETDEV_CHANGEMTU:
 		/* TODO: Should slaves be allowed to
 		 * independently alter their MTU?  For