Coverity complains that we have an unbalance use of mutex leading to
potential deadlocks.
Fixes: CID 1519048
Fixes: a208ba09bd ("tests/plugin: add a hotblocks plugin")
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-26-alex.bennee@linaro.org>
5b982f3bde