media: dvb_usb_pctv452e: module refcount changes were unbalanced

dvb_frontend will call dvb_detach for:
- stb0899_detach in dvb_frontend_release and
- stb0899_release in __dvb_frontend_free

But we only do dvb_attach(stb0899_attach).
Increment the module refcount instead.
Signed-off-by: Wolfgang Rohdewald <wolfgang@rohdewald.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/dvb-usb/pctv452e.c

@@ -913,6 +913,14 @@ static int pctv452e_frontend_attach(struct dvb_usb_adapter *a)
 						&a->dev->i2c_adap);
 	if (!a->fe_adap[0].fe)
 		return -ENODEV;
+
+	/*
+	 * dvb_frontend will call dvb_detach for both stb0899_detach
+	 * and stb0899_release but we only do dvb_attach(stb0899_attach).
+	 * Increment the module refcount instead.
+	 */
+	symbol_get(stb0899_attach);
+
 	if ((dvb_attach(lnbp22_attach, a->fe_adap[0].fe,
 					&a->dev->i2c_adap)) == NULL)
 		err("Cannot attach lnbp22\n");