tracing::trace_state: don't throw in a destructor
tracing::trace_state: don't throw in a destructor

The condition in question is sanity check for a SW bug.

This SW bug (if occurs) is not critical - there is an additional protection
against it in the stop_foreground_and_write().

Having said all that, since we shell not throw from a destructor,
replace throwing of a std::logic_error with an logger error message.

Signed-off-by: Vlad Zolotarov <976c0f8d0852ed6439ad273880b400a75a7c41d0@cloudius-systems.com>
Message-Id: <1471773320-7398-1-git-send-email-976c0f8d0852ed6439ad273880b400a75a7c41d0@cloudius-systems.com>

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