mac80211: remove sta_remove_debugfs driver callback

No drivers implement this, relying either on the recursive
directory removal to remove their debugfs, or not having any
to start with. Remove the dead driver callback.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 08bac23..d9c8ccd 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -3101,11 +3101,8 @@
  *
  * @sta_add_debugfs: Drivers can use this callback to add debugfs files
  *	when a station is added to mac80211's station list. This callback
- *	and @sta_remove_debugfs should be within a CONFIG_MAC80211_DEBUGFS
- *	conditional. This callback can sleep.
- *
- * @sta_remove_debugfs: Remove the debugfs files which were added using
- *	@sta_add_debugfs. This callback can sleep.
+ *	should be within a CONFIG_MAC80211_DEBUGFS conditional. This
+ *	callback can sleep.
  *
  * @sta_notify: Notifies low level driver about power state transition of an
  *	associated station, AP,  IBSS/WDS/mesh peer etc. For a VIF operating
@@ -3501,10 +3498,6 @@
 				struct ieee80211_vif *vif,
 				struct ieee80211_sta *sta,
 				struct dentry *dir);
-	void (*sta_remove_debugfs)(struct ieee80211_hw *hw,
-				   struct ieee80211_vif *vif,
-				   struct ieee80211_sta *sta,
-				   struct dentry *dir);
 #endif
 	void (*sta_notify)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			enum sta_notify_cmd, struct ieee80211_sta *sta);