Apparently, there's no clang-3.8 for Ubuntu Trusty arm64. The latest
available version is 3.6, let's try to use it.

https://travis-ci.org/kolyshkin/criu/builds/173168198Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>