bonding: fix slave speed reporting in bond_miimon_commit

When we have BOND_LINK_UP the speed is reported unconditionally with %u
format although it can be SPEED_UNKNOWN (-1). After this patch it returns
0 in that case in an attempt to keep the existing scripts happy.
One line is intenionally left 81 chars because it gets ugly if broken.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -2413,7 +2413,8 @@ static void bond_miimon_commit(struct bonding *bond)
 
 			pr_info("%s: link status definitely up for interface %s, %u Mbps %s duplex.\n",
 				bond->dev->name, slave->dev->name,
-				slave->speed, slave->duplex ? "full" : "half");
+				slave->speed == SPEED_UNKNOWN ? 0 : slave->speed,
+				slave->duplex ? "full" : "half");
 
 			/* notify ad that the link status has changed */
 			if (bond->params.mode == BOND_MODE_8023AD)