[v2] Bluetooth: btusb: Add return ENOBUFS error code

[Youwan Wang <youwan@xxxxxxxxxxxx>]

Convenient to check if the function was executed successfully
and know the specific error location in the code.

Signed-off-by: Youwan Wang <youwan@xxxxxxxxxxxx>
---
 drivers/bluetooth/btusb.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index d793dcd06687..a7244a8a5b7c 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -2824,8 +2824,10 @@ static int btusb_mtk_hci_wmt_sync(struct hci_dev *hdev,
 		goto err_free_wc;
 	}
 
-	if (data->evt_skb == NULL)
+	if (data->evt_skb == NULL) {
+		err = -ENOBUFS;
 		goto err_free_wc;
+	}
 
 	/* Parse and handle the return WMT event */
 	wmt_evt = (struct btmtk_hci_wmt_evt *)data->evt_skb->data;
-- 
2.25.1