Coverity CID 1390586; The cq handle is provided by the guest
and cannot be trusted to be previuosly allocated.
Fix it by exiting the completion flow.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Message-Id: <20180430200223.4119-3-marcel.apfelbaum@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>