Before the chardev name fix, the following error may happen: "attempt
to add duplicate property 'chr-test' to object (type 'container')",
due to races.

Sadly, error_vprintf() uses g_test_message(), so you have to use
read the cryptic --debug-log to see it. Later, it would make sense to
use g_critical() instead, and catch errors with
g_test_expect_message() (in glib 2.34).
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180215212552.26997-5-marcandre.lureau@redhat.com>
Acked-by: NMaxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>