ath10k: Add WARN_ON if we over-write peer-map pointer.

Not sure this can happen, but seems like a reasonable sanity
check.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/txrx.c

@@ -217,6 +217,7 @@ void ath10k_peer_map_event(struct ath10k_htt *htt,
 	ath10k_dbg(ar, ATH10K_DBG_HTT, "htt peer map vdev %d peer %pM id %d\n",
 		   ev->vdev_id, ev->addr, ev->peer_id);
 
+	WARN_ON(ar->peer_map[ev->peer_id] && (ar->peer_map[ev->peer_id] != peer));
 	ar->peer_map[ev->peer_id] = peer;
 	set_bit(ev->peer_id, peer->peer_ids);
 exit: