vlan_dev: return 0 on vlan_dev_change_mtu success

The VLAN net driver needs to return 0 from vlan_dev_change_mtu() on success.

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The proper sucessful return code for the change_mtu() method is zero. For some reason, vlan_dev_change_mtu() is returning the new mtu value instead.

 net/8021q/vlan_dev.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)

@@ -527,7 +527,7 @@
 
 	dev->mtu = new_mtu;
 
-	return new_mtu;
+	return 0;
 }
 
 int vlan_dev_set_ingress_priority(char *dev_name, __u32 skb_prio, short vlan_prio)

Both 2.4.x and 2.6.x variants applied, thanks John.