qga: Improve guest-exec-status error message

When the PID passed to guest-exec-status does not exist, we report

    "Invalid parameter 'pid'"

Improve this to

    "PID 1234 does not exist"

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20231031111059.3407803-4-armbru@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
1 file changed