[media] dvb_frontend: tuner_ops.release returns void

It is not clear what this return value means.  All implemenations
return 0, and the one caller ignores the value.  Let's remove this
useless return value completely.

Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/dvb-usb-v2/mxl111sf-tuner.c

@@ -455,13 +455,12 @@ static int mxl111sf_tuner_get_if_frequency(struct dvb_frontend *fe,
 	return 0;
 }
 
-static int mxl111sf_tuner_release(struct dvb_frontend *fe)
+static void mxl111sf_tuner_release(struct dvb_frontend *fe)
 {
 	struct mxl111sf_tuner_state *state = fe->tuner_priv;
 	mxl_dbg("()");
 	kfree(state);
 	fe->tuner_priv = NULL;
-	return 0;
 }
 
 /* ------------------------------------------------------------------------- */