mac80211: add tracing for ieee80211_sta_set_buffered

This is useful for debugging issues with drivers using this
function (erroneously), so add tracing for the API call.

Change-Id: Ice9d7eabb8fecbac188f0a741920d3488de700ec
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 4576ba0..8da3af2 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -1485,6 +1485,8 @@
 	if (WARN_ON(tid >= IEEE80211_NUM_TIDS))
 		return;
 
+	trace_api_sta_set_buffered(sta->local, pubsta, tid, buffered);
+
 	if (buffered)
 		set_bit(tid, &sta->driver_buffered_tids);
 	else