BUG_ON cleanup in drivers/net/tokenring/

This patch converts one if() BUG(); to BUG_ON();
so it can be safely optimized away.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

drivers/net/tokenring/tmspci.c

@@ -224,8 +224,7 @@ static void __devexit tms_pci_detach (struct pci_dev *pdev)
 {
 	struct net_device *dev = pci_get_drvdata(pdev);
 
-	if (!dev)
-		BUG();
+	BUG_ON(!dev);
 	unregister_netdev(dev);
 	release_region(dev->base_addr, TMS_PCI_IO_EXTENT);
 	free_irq(dev->irq, dev);