wifi: mac80211: warn only once on AP probe

We should perhaps support this API for MLO, but it's not
clear that it makes sense, in any case then we'd have to
update it to probe the correct BSS.

For now, if it happens, warn only once so that we don't
get flooded with messages if the driver misbehaves and
calls this.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230301115906.1c8499b6fbe6.I1a76a2be3b42ff93904870ac069f0319507adc23@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -3227,7 +3227,7 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 	bool already = false;
 
-	if (WARN_ON(sdata->vif.valid_links))
+	if (WARN_ON_ONCE(sdata->vif.valid_links))
 		return;
 
 	if (!ieee80211_sdata_running(sdata))