[media] DVB: dvb_frontend: avoid possible race condition on first event

  enqueued before the frontend thread wakes up.

Signed-off-by: Andreas Oberritter <obi@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/dvb-core/dvb_frontend.c

@@ -1891,8 +1891,8 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
 		/* Request the search algorithm to search */
 		fepriv->algo_status |= DVBFE_ALGO_SEARCH_AGAIN;
 
-		dvb_frontend_wakeup(fe);
 		dvb_frontend_add_event(fe, 0);
+		dvb_frontend_wakeup(fe);
 		fepriv->status = 0;
 		err = 0;
 		break;