Revert "mac80211: clear sta.drv_priv on reconfiguration"

This reverts commit f785d83a19bca326f79d127a413e35769afc0105.

This was provoking WARNINGs from the iwlegacy drivers.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 0c94907..6719bce 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1038,7 +1038,6 @@
 					     struct ieee80211_sub_if_data,
 					     u.ap);
 
-			memset(&sta->sta.drv_priv, 0, hw->sta_data_size);
 			WARN_ON(drv_sta_add(local, sdata, &sta->sta));
 		}
 	}