BUG_ON() Conversion in fs/hfsplus/

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/fs/hfsplus/btree.c b/fs/hfsplus/btree.c
index a67edfa..effa899 100644
--- a/fs/hfsplus/btree.c
+++ b/fs/hfsplus/btree.c
@@ -269,8 +269,7 @@
 	u8 *data, byte, m;
 
 	dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
-	if (!node->this)
-		BUG();
+	BUG_ON(!node->this);
 	tree = node->tree;
 	nidx = node->this;
 	node = hfs_bnode_find(tree, 0);