vhost-vsock: fix error message output

error_setg_errno takes a positive error number, so we should not invert
errno's sign.

Signed-off-by: Nick Erdmann <n@nirf.de>
Message-Id: <04df3f47-c93b-1d02-d250-f9bda8dbc0fa@nirf.de>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Fixes: fc0b9b0 ("vhost-vsock: add virtio sockets device")
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/virtio/vhost-vsock.c

@@ -325,7 +325,7 @@ static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
     } else {
         vhostfd = open("/dev/vhost-vsock", O_RDWR);
         if (vhostfd < 0) {
-            error_setg_errno(errp, -errno,
+            error_setg_errno(errp, errno,
                              "vhost-vsock: failed to open vhost device");
             return;
         }