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/dp_tx.c

@@ -4635,7 +4635,7 @@ dp_tx_comp_process_desc_list(struct dp_soc *soc,
 	struct dp_txrx_peer *txrx_peer = NULL;
 	uint16_t peer_id = DP_INVALID_PEER;
 	qdf_nbuf_t netbuf;
-	dp_txrx_ref_handle txrx_ref_handle;
+	dp_txrx_ref_handle txrx_ref_handle = NULL;
 
 	desc = comp_head;