can: gs_usb: gs_can_open(): prevent memory leak

In gs_can_open() if usb_submit_urb() fails the allocated urb should be
released.

Fixes: d08e973 ("can: gs_usb: Added support for the GS_USB CAN devices")
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/gs_usb.c

@@ -623,6 +623,7 @@ static int gs_can_open(struct net_device *netdev)
 					   rc);
 
 				usb_unanchor_urb(urb);
+				usb_free_urb(urb);
 				break;
 			}