check: skip mnt_id support check for mainstream kernels (v2)

v2: s/tun/mnt_id
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
log: Include inttypes.h for PRI helpers

https://bugzilla.openvz.org/show_bug.cgi?id=2949

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>