[netdrvr] kill sync_irq-before-freq_irq pattern

synchronize_irq() is superfluous when free_irq() call immediately follows it,
because free_irq() also does a synchronize_irq() call of its own.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/pci-skeleton.c

@@ -1739,7 +1739,6 @@ static int netdrv_close (struct net_device *dev)
 
 	spin_unlock_irqrestore (&tp->lock, flags);
 
-	synchronize_irq (dev->irq);
 	free_irq (dev->irq, dev);
 
 	netdrv_tx_clear (dev);