bdi: test bdi_init failure

There were two places where return value from bdi_init was not tested.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/mm/swap.c b/mm/swap.c
index 759c3ca..7a9f80d 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -934,7 +934,8 @@
 #ifdef CONFIG_SWAP
 	int i;
 
-	bdi_init(swapper_spaces[0].backing_dev_info);
+	if (bdi_init(swapper_spaces[0].backing_dev_info))
+		panic("Failed to init swap bdi");
 	for (i = 0; i < MAX_SWAPFILES; i++) {
 		spin_lock_init(&swapper_spaces[i].tree_lock);
 		INIT_LIST_HEAD(&swapper_spaces[i].i_mmap_nonlinear);