bonding: 802.3ad replace MAC_ADDRESS_EQUAL with __agg_has_partner

Replace macro MAC_ADDRESS_EQUAL() for null_mac_addr checking with inline
function__agg_has_partner(). When MAC_ADDRESS_EQUAL() is verifiying
aggregator's partner mac addr with null_mac_addr, means that seeing if
aggregator has a valid partner or not. Using __agg_has_partner() makes it
more clear to understand.

In ad_port_selection_logic(), since aggregator->partner_system and
port->partner_oper.system has been compared first as a prerequisite, it is
safe to replace the upcoming MAC_ADDRESS_EQUAL() for null_mac_addr checking
with __agg_has_partner().

Delete null_mac_addr, which is not required anymore in bond_3ad.c, since
all references to it are gone.
Signed-off-by: Jones Syue <jonessyue@qnap.com>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Link: https://lore.kernel.org/r/SI2PR04MB5097BCA8FF2A2F03D9A5A3EEDC5A2@SI2PR04MB5097.apcprd04.prod.outlook.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/bonding/bond_3ad.c

@@ -82,10 +82,6 @@ enum ad_link_speed_type {
 #define MAC_ADDRESS_EQUAL(A, B)	\
 	ether_addr_equal_64bits((const u8 *)A, (const u8 *)B)
 
-static const u8 null_mac_addr[ETH_ALEN + 2] __long_aligned = {
-	0, 0, 0, 0, 0, 0
-};
-
 static const u16 ad_ticks_per_sec = 1000 / AD_TIMER_INTERVAL;
 static const int ad_delta_in_ticks = (AD_TIMER_INTERVAL * HZ) / 1000;
 
@@ -1588,7 +1584,7 @@ static void ad_port_selection_logic(struct port *port, bool *update_slave_arr)
 		     (aggregator->partner_system_priority == port->partner_oper.system_priority) &&
 		     (aggregator->partner_oper_aggregator_key == port->partner_oper.key)
 		    ) &&
-		    ((!MAC_ADDRESS_EQUAL(&(port->partner_oper.system), &(null_mac_addr)) && /* partner answers */
+		    ((__agg_has_partner(aggregator) && /* partner answers */
 		      !aggregator->is_individual)  /* but is not individual OR */
 		    )
 		   ) {
@@ -2036,9 +2032,7 @@ static void ad_enable_collecting(struct port *port)
  */
 static void ad_disable_distributing(struct port *port, bool *update_slave_arr)
 {
-	if (port->aggregator &&
-	    !MAC_ADDRESS_EQUAL(&port->aggregator->partner_system,
-			       &(null_mac_addr))) {
+	if (port->aggregator && __agg_has_partner(port->aggregator)) {
 		slave_dbg(port->slave->bond->dev, port->slave->dev,
 			  "Disabling distributing on port %d (LAG %d)\n",
 			  port->actor_port_number,
@@ -2078,9 +2072,7 @@ static void ad_enable_collecting_distributing(struct port *port,
 static void ad_disable_collecting_distributing(struct port *port,
 					       bool *update_slave_arr)
 {
-	if (port->aggregator &&
-	    !MAC_ADDRESS_EQUAL(&(port->aggregator->partner_system),
-			       &(null_mac_addr))) {
+	if (port->aggregator && __agg_has_partner(port->aggregator)) {
 		slave_dbg(port->slave->bond->dev, port->slave->dev,
 			  "Disabling port %d (LAG %d)\n",
 			  port->actor_port_number,