[media] r820t: memory leak in release()

I've moved the kfree(fe->tuner_priv) one line earlier, otherwise it is
a no-op.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/tuners/r820t.c

@@ -2252,9 +2252,8 @@ static int r820t_release(struct dvb_frontend *fe)
 
 	mutex_unlock(&r820t_list_mutex);
 
-	fe->tuner_priv = NULL;
-
 	kfree(fe->tuner_priv);
+	fe->tuner_priv = NULL;
 
 	return 0;
 }