wifi: mac80211: don't unreserve never reserved chanctx

If a link has no chanctx, indicating it is an inactive link
that we tracked CSA for, then attempting to unreserve the
reserved chanctx will throw a warning and fail, since there
never was a reserved chanctx. Skip the unreserve.

Signed-off-by: Johannes Berg <[email protected]>
Signed-off-by: Miri Korenblit <[email protected]>
Link: https://patch.msgid.link/20250709233537.022192f4b1ae.Ib58156ac13e674a9f4d714735be0764a244c0aae@changeid
Signed-off-by: Johannes Berg <[email protected]>

Author: jmberg-intel

net/mac80211/mlme.c

@@ -2561,7 +2561,8 @@ ieee80211_sta_abort_chanswitch(struct ieee80211_link_data *link)
 	if (!local->ops->abort_channel_switch)
 		return;
 
-	ieee80211_link_unreserve_chanctx(link);
+	if (rcu_access_pointer(link->conf->chanctx_conf))
+		ieee80211_link_unreserve_chanctx(link);
 
 	ieee80211_vif_unblock_queues_csa(sdata);