BUG_ON() Conversion in drivers/isdn

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/isdn/hisax/hisax_isac.c b/drivers/isdn/hisax/hisax_isac.c
index f4972f6..81eac34 100644
--- a/drivers/isdn/hisax/hisax_isac.c
+++ b/drivers/isdn/hisax/hisax_isac.c
@@ -476,12 +476,10 @@
 	unsigned char cmd;
 	u_char *ptr;
 
-	if (!isac->tx_skb)
-		BUG();
+	BUG_ON(!isac->tx_skb);
 
 	count = isac->tx_skb->len;
-	if (count <= 0)
-		BUG();
+	BUG_ON(count <= 0);
 
 	DBG(DBG_IRQ, "count %d", count);
 
@@ -859,8 +857,7 @@
 			dev_kfree_skb(skb);
 			break;
 		}
-		if (isac->tx_skb)
-			BUG();
+		BUG_ON(isac->tx_skb);
 
 		isac->tx_skb = skb;
 		isac_fill_fifo(isac);