[PATCH] bonding: cleanup comment for mode 1 IGMP xmit hack

Expand comment explaining MAC address selection for replicated IGMP
frames transmitted in bonding mode 1 (active-backup).  Also, a small
whitespace cleanup.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/net/bonding/bond_main.c

@@ -4259,7 +4259,11 @@ static void bond_activebackup_xmit_copy(struct sk_buff *skb,
 	skb2->mac.raw = (unsigned char *)skb2->data;
 	eth_data = eth_hdr(skb2);
 
-	/* Pick an appropriate source MAC address */
+	/* Pick an appropriate source MAC address
+	 *	-- use slave's perm MAC addr, unless used by bond
+	 *	-- otherwise, borrow active slave's perm MAC addr
+	 *	   since that will not be used
+	 */
 	hwaddr = slave->perm_hwaddr;
 	if (!memcmp(eth_data->h_source, hwaddr, ETH_ALEN))
 		hwaddr = bond->curr_active_slave->perm_hwaddr;