[media] dvb_frontend: merge duplicate dvb_tuner_ops.release implementations

Most release callback functions are identical: free the "tuner_priv"
and clear it.  Let's eliminate some bloat by providing this simple
implementation in the dvb_frontend library.

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

drivers/media/tuners/tda18218.c

@@ -265,13 +265,6 @@ static int tda18218_init(struct dvb_frontend *fe)
 	return ret;
 }
 
-static int tda18218_release(struct dvb_frontend *fe)
-{
-	kfree(fe->tuner_priv);
-	fe->tuner_priv = NULL;
-	return 0;
-}
-
 static const struct dvb_tuner_ops tda18218_tuner_ops = {
 	.info = {
 		.name           = "NXP TDA18218",
@@ -281,7 +274,7 @@ static const struct dvb_tuner_ops tda18218_tuner_ops = {
 		.frequency_step =      1000,
 	},
 
-	.release       = tda18218_release,
+	.release       = dvb_tuner_simple_release,
 	.init          = tda18218_init,
 	.sleep         = tda18218_sleep,