Bluetooth: btusb: fix memory leak in btusb_mtk_submit_wmt_recv_urb()

Driver should free `usb->setup_packet` to avoid the leak.

$ cat /sys/kernel/debug/kmemleak
unreferenced object 0xffffffa564a58080 (size 128):
    backtrace:
        [<000000007eb8dd70>] kmem_cache_alloc_trace+0x22c/0x384
        [<000000008a44191d>] btusb_mtk_hci_wmt_sync+0x1ec/0x994
    [btusb]
        [<00000000ca7189a3>] btusb_mtk_setup+0x6b8/0x13cc
    [btusb]
        [<00000000c6105069>] hci_dev_do_open+0x290/0x974
    [bluetooth]
        [<00000000a583f8b8>] hci_power_on+0xdc/0x3cc [bluetooth]
        [<000000005d80e687>] process_one_work+0x514/0xc80
        [<00000000f4d57637>] worker_thread+0x818/0xd0c
        [<00000000dc7bdb55>] kthread+0x2f8/0x3b8
        [<00000000f9999513>] ret_from_fork+0x10/0x30

Fixes: a1c49c43 ("Bluetooth: btusb: Add protocol support for MediaTek MT7668U USB devices")
Signed-off-by: Mark-YW.Chen <mark-yw.chen@mediatek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btusb.c

@@ -2265,6 +2265,7 @@ static void btusb_mtk_wmt_recv(struct urb *urb)
 		skb = bt_skb_alloc(HCI_WMT_MAX_EVENT_SIZE, GFP_ATOMIC);
 		if (!skb) {
 			hdev->stat.err_rx++;
+			kfree(urb->setup_packet);
 			return;
 		}
 
@@ -2285,6 +2286,7 @@ static void btusb_mtk_wmt_recv(struct urb *urb)
 			data->evt_skb = skb_clone(skb, GFP_ATOMIC);
 			if (!data->evt_skb) {
 				kfree_skb(skb);
+				kfree(urb->setup_packet);
 				return;
 			}
 		}
@@ -2293,6 +2295,7 @@ static void btusb_mtk_wmt_recv(struct urb *urb)
 		if (err < 0) {
 			kfree_skb(data->evt_skb);
 			data->evt_skb = NULL;
+			kfree(urb->setup_packet);
 			return;
 		}
 
@@ -2303,6 +2306,7 @@ static void btusb_mtk_wmt_recv(struct urb *urb)
 			wake_up_bit(&data->flags,
 				    BTUSB_TX_WAIT_VND_EVT);
 		}
+		kfree(urb->setup_packet);
 		return;
 	} else if (urb->status == -ENOENT) {
 		/* Avoid suspend failed when usb_kill_urb */
@@ -2323,6 +2327,7 @@ static void btusb_mtk_wmt_recv(struct urb *urb)
 	usb_anchor_urb(urb, &data->ctrl_anchor);
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (err < 0) {
+		kfree(urb->setup_packet);
 		/* -EPERM: urb is being killed;
 		 * -ENODEV: device got disconnected
 		 */