Eina lock: unused warning suppression is done with (void).
Eina lock: unused warning suppression is done with (void).

Not only that it's uglier doing mutex=0, but also new gcc started
complainig about it.

SVN revision: 59137

turran/eina,turran/eina,turran/eina,gfriloux/eina,gfriloux/eina,gfriloux/eina