[PATCH] lz4: fix decompressor on big-endian powerpc

[Julius Werner]

> I'm a bit puzzled about the github.com/Cyan4973/lz4
> reference. Cyan4973 is Yann Collet, the author of lz4, and nowadays at
> least that github url redirects to the upstream repo,
> github.com/lz4/lz4. Grepping through all available tags and branches
> there, the identifiers "has_content_checksum" and "lz4_frame_header" have
> never appeared anywhere in the source (and he uses camelCase).

That comment refers to the lz4.c file that's included by the line
right below it. That was copied 1-to-1 from Yann's code. The
lz4_wrapper.c file was written from scratch by me.

Reviewed-by: Julius Werner <jwerner at chromium.org>