checkpatch: check trace-events code style

According to CODING_STYLE, check that in trace-events:
1. hex numbers are prefixed with '0x'
2. '#' flag of printf is not used
3. The exclusion from 1. are period-separated groups of numbers

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170731160135.12101-4-vsementsov@virtuozzo.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
