[media] cxd2820r: remove unused parameter from cxd2820r_attach

Fix bug introduced by multi-frontend to single-frontend change.
This parameter is no longer used after multi-frontend to single-frontend change.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/em28xx/em28xx-dvb.c b/drivers/media/video/em28xx/em28xx-dvb.c
index 9449423..aabbf48 100644
--- a/drivers/media/video/em28xx/em28xx-dvb.c
+++ b/drivers/media/video/em28xx/em28xx-dvb.c
@@ -853,8 +853,7 @@
 	case EM28174_BOARD_PCTV_290E:
 		dvb->fe[0] = dvb_attach(cxd2820r_attach,
 					&em28xx_cxd2820r_config,
-					&dev->i2c_adap,
-					NULL);
+					&dev->i2c_adap);
 		if (dvb->fe[0]) {
 			/* FE 0 attach tuner */
 			if (!dvb_attach(tda18271_attach,