can: kvaser_usb: kvaser_usb_set_bittiming(): fix redundant initialization warning for err

The variable err is initialized, but the initialized value is
Overwritten before it is read. Fix the warning by not initializing the
variable err at all.

Fixes: 39d3df6b ("can: kvaser_usb: Compare requested bittiming parameters with actual parameters in do_set_{,data}_bittiming")
Cc: Jimmy Assarsson <extja@kvaser.com>
Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
Link: https://lore.kernel.org/all/20221031114513.81214-1-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c

@@ -541,7 +541,7 @@ static int kvaser_usb_set_bittiming(struct net_device *netdev)
 	int tseg1 = bt->prop_seg + bt->phase_seg1;
 	int tseg2 = bt->phase_seg2;
 	int sjw = bt->sjw;
-	int err = -EOPNOTSUPP;
+	int err;
 
 	busparams.bitrate = cpu_to_le32(bt->bitrate);
 	busparams.sjw = (u8)sjw;