V4L/DVB (12869): tda18271: fix comments and make tda18271_agc debug less verbose

Don't display "no agc configuration provided" unless DBG_ADV is set.

Fix comments in function, tda18271_agc.  This config variable is not
for LNA configuration -- it is for external AGC configuration.
Signed-off-by: Michael Krufky <mkrufky@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/common/tuners/tda18271-fe.c

@@ -863,7 +863,8 @@ static int tda18271_agc(struct dvb_frontend *fe)
 
 	switch (priv->config) {
 	case 0:
-		/* no LNA */
+		/* no external agc configuration required */
+		if (tda18271_debug & DBG_ADV)
 			tda_dbg("no agc configuration provided\n");
 		break;
 	case 3: