[VLAN]: Avoid a 4-order allocation.

This patch splits the vlan_group struct into a multi-allocated struct. On
x86_64, the size of the original struct is a little more than 32KB, causing
a 4-order allocation, which is prune to problems caused by buddy-system
external fragmentation conditions.

I couldn't just use vmalloc() because vfree() cannot be called in the
softirq context of the RCU callback.

Signed-off-by: Dan Aloni <da-x@monatomic.org>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/8139cp.c b/drivers/net/8139cp.c
index 6f93a76..12c8453 100644
--- a/drivers/net/8139cp.c
+++ b/drivers/net/8139cp.c
@@ -448,8 +448,7 @@
 	spin_lock_irqsave(&cp->lock, flags);
 	cp->cpcmd &= ~RxVlanOn;
 	cpw16(CpCmd, cp->cpcmd);
-	if (cp->vlgrp)
-		cp->vlgrp->vlan_devices[vid] = NULL;
+	vlan_group_set_device(cp->vlgrp, vid, NULL);
 	spin_unlock_irqrestore(&cp->lock, flags);
 }
 #endif /* CP_VLAN_TAG_USED */