bonding: comparing a u8 with -1 is always false

slave->duplex is a u8 type so the in bond_info_show_slave() when we
check "if (slave->duplex == -1)", it's always false.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_procfs.c b/drivers/net/bonding/bond_procfs.c
index d2ff52e..17206da 100644
--- a/drivers/net/bonding/bond_procfs.c
+++ b/drivers/net/bonding/bond_procfs.c
@@ -157,12 +157,12 @@
 	seq_printf(seq, "\nSlave Interface: %s\n", slave->dev->name);
 	seq_printf(seq, "MII Status: %s\n",
 		   (slave->link == BOND_LINK_UP) ?  "up" : "down");
-	if (slave->speed == -1)
+	if (slave->speed == SPEED_UNKNOWN)
 		seq_printf(seq, "Speed: %s\n", "Unknown");
 	else
 		seq_printf(seq, "Speed: %d Mbps\n", slave->speed);
 
-	if (slave->duplex == -1)
+	if (slave->duplex == DUPLEX_UNKNOWN)
 		seq_printf(seq, "Duplex: %s\n", "Unknown");
 	else
 		seq_printf(seq, "Duplex: %s\n", slave->duplex ? "full" : "half");