Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/can/usb/ucan.c: In function 'ucan_disconnect':
drivers/net/can/usb/ucan.c:1578:21: warning:
 variable 'udev' set but not used [-Wunused-but-set-variable]
  struct usb_device *udev;

Signed-off-by: YueHaibing <redacted>
---
 drivers/net/can/usb/ucan.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/can/usb/ucan.c b/drivers/net/can/usb/ucan.c
index 0678a38..c9fd83e 100644
--- a/drivers/net/can/usb/ucan.c
+++ b/drivers/net/can/usb/ucan.c

@@ -1575,11 +1575,8 @@ static int ucan_probe(struct usb_interface *intf,
 /* disconnect the device */
 static void ucan_disconnect(struct usb_interface *intf)
 {
-	struct usb_device *udev;
 	struct ucan_priv *up = usb_get_intfdata(intf);
 
-	udev = interface_to_usbdev(intf);
-
 	usb_set_intfdata(intf, NULL);
 
 	if (up) {