tests/qtest: Fix two format strings

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Message-Id: <20221105115525.623059-1-sw@weilnetz.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
1 file changed