[PATCH] erofs: drop unnecessary WARN_ON() in erofs_kill_sb()

[Christoph Hellwig]

On Tue, Aug 01, 2023 at 09:47:37AM +0800, Gao Xiang wrote:
> Previously, .kill_sb() will be called only after fill_super fails.
> It will be changed [1].
> 
> Besides, checking for s_magic in erofs_kill_sb() is unnecessary from
> any point of view.  Let's get rid of it now.

Looks good:

Reviewed-by: Christoph Hellwig <hch at lst.de>