mac80211: fix a possible leak of station stats

If sta_info_alloc fails after allocating the per CPU statistics,
they are not properly freed.

Fixes: c9c5962b56c1 ("mac80211: enable collecting station statistics per-CPU")
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/sta_info.c

@@ -433,6 +433,7 @@ free_txq:
 	if (sta->sta.txq[0])
 		kfree(to_txq_info(sta->sta.txq[0]));
 free:
+	free_percpu(sta->pcpu_rx_stats);
 #ifdef CONFIG_MAC80211_MESH
 	kfree(sta->mesh);
 #endif