BUG_ON() Conversion in drivers/net/

this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/net/starfire.c b/drivers/net/starfire.c
index 35b1805..45ad036 100644
--- a/drivers/net/starfire.c
+++ b/drivers/net/starfire.c
@@ -2122,8 +2122,7 @@
 	struct net_device *dev = pci_get_drvdata(pdev);
 	struct netdev_private *np = netdev_priv(dev);
 
-	if (!dev)
-		BUG();
+	BUG_ON(!dev);
 
 	unregister_netdev(dev);