Btrfs: actually call btrfs_init_lockdep

btrfs_init_lockdep only makes our lockdep class names look prettier, thus
it did never hurt we forgot to actually call it. This turns our lockdep
identifier strings from lockdep auto-set #[id] into really pretty
"btrfs-fs-01" or "btrfs-csum-03".

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>

fs/btrfs/super.c

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 61717a4..5239003 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1404,6 +1404,8 @@
 	if (err)
 		goto unregister_ioctl;
 
+	btrfs_init_lockdep();
+
 	printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
 	return 0;