Backport vmbus trace points

[rn]

4.15.x has trace point instrumentation for some of the VMBus functions. We should consider backporting them to at least 4.14.x. They may help with things like linuxkit/virtsock#55 and #2724

Specifically:

259cc665e9c0 ("hyper-v: trace vmbus_release_relid()")
d6706e63367a ("hyper-v: trace vmbus_request_offers()")
c7924fb07a26 ("hyper-v: trace vmbus_onversion_response()")
602a8c525c8c ("hyper-v: trace vmbus_ongpadl_torndown()")
a13bf0ea4a60 ("hyper-v: trace vmbus_ongpadl_created()")
9f23ce1a23b6 ("hyper-v: trace vmbus_onopen_result()")
5175167c77af ("hyper-v: trace vmbus_onoffer_rescind()")
03b81e66c78b ("hyper-v: trace vmbus_onoffer()")
716fa52fb474 ("hyper-v: trace vmbus_on_message()")