media: ttusb-dec: fix memory leak in ttusb_dec_exit_dvb()

[ Upstream commit 517a281 ]

Since dvb_frontend_detach() is not called in ttusb_dec_exit_dvb(),
which is called when the device is disconnected, dvb_frontend_free()
is not finally called.

This causes a memory leak just by repeatedly plugging and
unplugging the device.

Fix this issue by adding dvb_frontend_detach() to ttusb_dec_exit_dvb().

Link: https://lore.kernel.org/linux-media/20221117045925.14297-5-imv4bel@gmail.com
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/media/usb/ttusb-dec/ttusb_dec.c

@@ -1544,8 +1544,7 @@ static void ttusb_dec_exit_dvb(struct ttusb_dec *dec)
 	dvb_dmx_release(&dec->demux);
 	if (dec->fe) {
 		dvb_unregister_frontend(dec->fe);
-		if (dec->fe->ops.release)
-			dec->fe->ops.release(dec->fe);
+		dvb_frontend_detach(dec->fe);
 	}
 	dvb_unregister_adapter(&dec->adapter);
 }