[PATCH] erofs-utils: add Apache 2.0 license

[Gao Xiang]

Hi Jianan,

Personally, I'm very happy to dual-license liberofs from
now.

On Wed, Dec 01, 2021 at 11:59:52PM +0800, Huang Jianan wrote:
> Add Apache 2.0 to license for liberofs.

Let's release liberofs under GPL-2.0+ OR Apache-2.0 license
for better integration.

> 
> Signed-off-by: Huang Jianan <huangjianan at oppo.com>
> ---

...

>  include/erofs/flex-array.h     | 2 +-
>  include/erofs/hashmap.h        | 2 +-
>  include/erofs/hashtable.h      | 2 +-

I think we may not change these three files for now.
Maybe we need to find some alternative for these later.

Also, it would be much better to get others Acked-by
(especially Li Guifu) as many as possible.

Thanks,
Gao Xiang