mac80211: add missing CSA locking

The patch adds a missing sdata lock and adds a few
lockdeps for easier maintenance.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index bd55115..f70e9cd 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -864,6 +864,8 @@
 	int err;
 	u32 sta_flags;
 
+	sdata_assert_lock(sdata);
+
 	sta_flags = IEEE80211_STA_DISABLE_VHT;
 	switch (sdata->vif.bss_conf.chandef.width) {
 	case NL80211_CHAN_WIDTH_20_NOHT: