qcacmn: Initialize txrx_ref_handle for whunt bypass

Initialize txrx_ref_handle for whunt bypass,
Which is complaining use of uninitialized txrx_ref_handle,
as it is not able to detect that txrx_ref_handle is
populated from another API.

Change-Id: I0f69cf4c8442a5655559622a5825d7af35b9ae5e
CRs-Fixed: 3127788

dp/wifi3.0/be/dp_be_tx.c

@@ -183,7 +183,7 @@ void dp_tx_process_htt_completion_be(struct dp_soc *soc,
 	struct hal_tx_completion_status ts = {0};
 	uint32_t *htt_desc = (uint32_t *)status;
 	struct dp_txrx_peer *txrx_peer;
-	dp_txrx_ref_handle txrx_ref_handle;
+	dp_txrx_ref_handle txrx_ref_handle = NULL;
 	struct cdp_tid_tx_stats *tid_stats = NULL;
 	struct htt_soc *htt_handle;
 	uint8_t vdev_id;