mac80211: call drv_ibss_join() on restart

If a driver does any significant activity in its ibss_join method,
then it will very well expect that to be called during restart,
before any stations are added. Do that.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/util.c

@@ -5,7 +5,7 @@
  * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright (C) 2015-2017	Intel Deutschland GmbH
- * Copyright (C) 2018 Intel Corporation
+ * Copyright (C) 2018-2019 Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -2146,6 +2146,10 @@ int ieee80211_reconfig(struct ieee80211_local *local)
 		case NL80211_IFTYPE_AP_VLAN:
 		case NL80211_IFTYPE_MONITOR:
 			break;
+		case NL80211_IFTYPE_ADHOC:
+			if (sdata->vif.bss_conf.ibss_joined)
+				WARN_ON(drv_join_ibss(local, sdata));
+			/* fall through */
 		default:
 			ieee80211_reconfig_stations(sdata);
 			/* fall through */