ubifs: Move ui->data initialization after initializing security

ubifs: Move ui->data initialization after initializing security

Host inode and its' xattr will be written on disk after initializing
security when creating symlink or dev, then the host inode and its
dentry will be written again in ubifs_jnl_update.
There is no need to write inode data in the security initialization
pass, just move the ui->data initialization after initializing
security.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>