[BOND]: Fix warning in bond_sysfs.c

original_mtu is only used if we end up with a non-NULL
dev, and it is assigned in all such cases, but GCC can't
see that.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 90a1f31..979c2d0 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -341,6 +341,7 @@
 
 	if (command[0] == '-') {
 		dev = NULL;
+		original_mtu = 0;
 		bond_for_each_slave(bond, slave, i)
 			if (strnicmp(slave->dev->name, ifname, IFNAMSIZ) == 0) {
 				dev = slave->dev;