test/zdtm: use separate compile/link

For compatibility with ccache (so it can cache the compilation results),
let's compile and link separately. For this, we have to
 - disable the implicit make rules
 - write the explicit ones

While at it, do use the "silent make" stuff that is already here

FIXME: figure out if it helps to speed up ccache build

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>