media: pci: cx23885: fix error handling for cx23885 ATSC boards

After having been assigned to NULL value at cx23885-dvb.c:1202,
pointer '0' is dereferenced at cx23885-dvb.c:2469.

Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Nikolay Burykin <burikin@ivk.ru>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/pci/cx23885/cx23885-dvb.c

@@ -2459,16 +2459,10 @@ static int dvb_register(struct cx23885_tsport *port)
 			request_module("%s", info.type);
 			client_tuner = i2c_new_client_device(&dev->i2c_bus[1].i2c_adap, &info);
 			if (!i2c_client_has_driver(client_tuner)) {
-				module_put(client_demod->dev.driver->owner);
-				i2c_unregister_device(client_demod);
-				port->i2c_client_demod = NULL;
 				goto frontend_detach;
 			}
 			if (!try_module_get(client_tuner->dev.driver->owner)) {
 				i2c_unregister_device(client_tuner);
-				module_put(client_demod->dev.driver->owner);
-				i2c_unregister_device(client_demod);
-				port->i2c_client_demod = NULL;
 				goto frontend_detach;
 			}
 			port->i2c_client_tuner = client_tuner;
@@ -2505,16 +2499,10 @@ static int dvb_register(struct cx23885_tsport *port)
 			request_module("%s", info.type);
 			client_tuner = i2c_new_client_device(&dev->i2c_bus[1].i2c_adap, &info);
 			if (!i2c_client_has_driver(client_tuner)) {
-				module_put(client_demod->dev.driver->owner);
-				i2c_unregister_device(client_demod);
-				port->i2c_client_demod = NULL;
 				goto frontend_detach;
 			}
 			if (!try_module_get(client_tuner->dev.driver->owner)) {
 				i2c_unregister_device(client_tuner);
-				module_put(client_demod->dev.driver->owner);
-				i2c_unregister_device(client_demod);
-				port->i2c_client_demod = NULL;
 				goto frontend_detach;
 			}
 			port->i2c_client_tuner = client_tuner;