bug#23075: 24.5; vc-git-command should use coding-system-for-read

[Eli Zaretskii]

> From: Óscar Fuentes <ofv@wanadoo.es>
> Cc: Eli Zaretskii <eliz@gnu.org>,  23075@debbugs.gnu.org,  Nikolay 
> Kudryavtsev <nikolay.kudryavtsev@gmail.com>
> Date: Mon, 21 Mar 2016 19:05:11 +0100
> 
> Does git always use that encoding? If not, on what it depends the
> encoding used by git?

It just spews the bytes, AFAIK.  IOW, it's the encoding of the file
whose log we are viewing.