nbd: pass the nbd pointer for flags debugfs

We were passing in &nbd for the private data in debugfs_create_file() for the
flags entry.  We expect it to just be nbd, fix this so we get proper output from
this debugfs entry.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/block/nbd.c

@@ -941,7 +941,7 @@ static int nbd_dev_dbg_init(struct nbd_device *nbd)
 	debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize);
 	debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout);
 	debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize);
-	debugfs_create_file("flags", 0444, dir, &nbd, &nbd_dbg_flags_ops);
+	debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops);
 
 	return 0;
 }