Btrfs: BUG to BUG_ON changes

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b808276..e5b2533 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2157,8 +2157,7 @@
 	BUG_ON(!path->nodes[level]);
 	lower = path->nodes[level];
 	nritems = btrfs_header_nritems(lower);
-	if (slot > nritems)
-		BUG();
+	BUG_ON(slot > nritems);
 	if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
 		BUG();
 	if (slot != nritems) {