media: gp8psk: initialize stats at power control logic

As reported on:
	https://lore.kernel.org/linux-media/20190627222020.45909-1-willemdebruijn.kernel@gmail.com/

if gp8psk_usb_in_op() returns an error, the status var is not
initialized. Yet, this var is used later on, in order to
identify:
	- if the device was already started;
	- if firmware has loaded;
	- if the LNBf was powered on.

Using status = 0 seems to ensure that everything will be
properly powered up.

So, instead of the proposed solution, let's just set
status = 0.

Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/usb/dvb-usb/gp8psk.c

@@ -182,7 +182,7 @@ static int gp8psk_load_bcm4500fw(struct dvb_usb_device *d)
 
 static int gp8psk_power_ctrl(struct dvb_usb_device *d, int onoff)
 {
-	u8 status, buf;
+	u8 status = 0, buf;
 	int gp_product_id = le16_to_cpu(d->udev->descriptor.idProduct);
 
 	if (onoff) {