Use DECLARE_FLEX_ARRAY() helper in drivers/net/can/usb/ucan.c

[GustavoARSilva]

diff -u -p ./drivers/net/can/usb/ucan.c /tmp/nothing/drivers/net/can/usb/ucan.c
--- ./drivers/net/can/usb/ucan.c
+++ /tmp/nothing/drivers/net/can/usb/ucan.c
@@ -245,7 +245,6 @@ struct ucan_message_in {
                /* CAN transmission complete
                 * (type == UCAN_IN_TX_COMPLETE)
                 */
-               struct ucan_tx_complete_entry_t can_tx_complete_msg[0];
        } __aligned(0x4) msg;
 } __packed __aligned(0x4);