bonding: adjust style of bond_3ad_rx_indication

No functional changes, adjust the style of bond_3ad_rx_indication to
prepare it for the stats changes:
 - reduce indentation by returning early on wrong length
 - remove extra new lines between switch cases
 - add marker local variable and use it to reduce line length
 - rearrange local variables in reverse xmas tree
 - separate final return
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_3ad.c

@@ -2357,13 +2357,14 @@ void bond_3ad_state_machine_handler(struct work_struct *work)
 static int bond_3ad_rx_indication(struct lacpdu *lacpdu, struct slave *slave,
 				  u16 length)
 {
-	struct port *port;
 	int ret = RX_HANDLER_ANOTHER;
+	struct bond_marker *marker;
+	struct port *port;
 
-	if (length >= sizeof(struct lacpdu)) {
+	if (length < sizeof(struct lacpdu))
+		return ret;
 
 	port = &(SLAVE_AD_INFO(slave)->port);
-
 	if (!port->slave) {
 		net_warn_ratelimited("%s: Warning: port of slave %s is uninitialized\n",
 				     slave->dev->name, slave->bond->dev->name);
@@ -2375,39 +2376,35 @@ static int bond_3ad_rx_indication(struct lacpdu *lacpdu, struct slave *slave,
 		ret = RX_HANDLER_CONSUMED;
 		netdev_dbg(slave->bond->dev,
 			   "Received LACPDU on port %d slave %s\n",
-				   port->actor_port_number,
-				   slave->dev->name);
+			   port->actor_port_number, slave->dev->name);
 		/* Protect against concurrent state machines */
 		spin_lock(&slave->bond->mode_lock);
 		ad_rx_machine(lacpdu, port);
 		spin_unlock(&slave->bond->mode_lock);
 		break;
-
 	case AD_TYPE_MARKER:
 		ret = RX_HANDLER_CONSUMED;
 		/* No need to convert fields to Little Endian since we
 		 * don't use the marker's fields.
 		 */
-
-			switch (((struct bond_marker *)lacpdu)->tlv_type) {
+		marker = (struct bond_marker *)lacpdu;
+		switch (marker->tlv_type) {
 		case AD_MARKER_INFORMATION_SUBTYPE:
 			netdev_dbg(slave->bond->dev, "Received Marker Information on port %d\n",
 				   port->actor_port_number);
-				ad_marker_info_received((struct bond_marker *)lacpdu, port);
+			ad_marker_info_received(marker, port);
 			break;
-
 		case AD_MARKER_RESPONSE_SUBTYPE:
 			netdev_dbg(slave->bond->dev, "Received Marker Response on port %d\n",
 				   port->actor_port_number);
-				ad_marker_response_received((struct bond_marker *)lacpdu, port);
+			ad_marker_response_received(marker, port);
 			break;
-
 		default:
 			netdev_dbg(slave->bond->dev, "Received an unknown Marker subtype on slot %d\n",
 				   port->actor_port_number);
 		}
 	}
-	}
+
 	return ret;
 }