vfs: for usbfs, etc. internal vfsmounts ->mnt_sb->s_root == ->mnt_root

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c
index 30883a7..d92f4ce 100644
--- a/fs/hppfs/hppfs.c
+++ b/fs/hppfs/hppfs.c
@@ -725,7 +725,7 @@
 	sb->s_fs_info = proc_mnt;
 
 	err = -ENOMEM;
-	root_inode = get_inode(sb, dget(proc_mnt->mnt_sb->s_root));
+	root_inode = get_inode(sb, dget(proc_mnt->mnt_root));
 	if (!root_inode)
 		goto out_mntput;