cfg80211: ignore channel state for stopped AP/mesh interfaces

Without this change, running AP + station on the same wiphy
does not work since the commit "cfg80211: add channel checking
for iface combinations". The stopped AP prevents the client
from connecting to an AP on a different channel.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
[line-break commit message to < 72 chars]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/chan.c

@@ -134,9 +134,16 @@ cfg80211_get_chan_state(struct wireless_dev *wdev,
 		break;
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_P2P_GO:
+		if (wdev->beacon_interval) {
+			*chan = wdev->channel;
+			*chanmode = CHAN_MODE_SHARED;
+		}
+		return;
 	case NL80211_IFTYPE_MESH_POINT:
-		*chan = wdev->channel;
-		*chanmode = CHAN_MODE_SHARED;
+		if (wdev->mesh_id_len) {
+			*chan = wdev->channel;
+			*chanmode = CHAN_MODE_SHARED;
+		}
 		return;
 	case NL80211_IFTYPE_MONITOR:
 	case NL80211_IFTYPE_AP_VLAN: