mac80211: read station mgmt keys via get_key call

Allow to read management keys stored in a station's gtk key
array with a get_key function.

Signed-off-by: Max Stepanov <Max.Stepanov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 0962c77..ac18528 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -303,7 +303,8 @@
 
 		if (pairwise && key_idx < NUM_DEFAULT_KEYS)
 			key = rcu_dereference(sta->ptk[key_idx]);
-		else if (!pairwise && key_idx < NUM_DEFAULT_KEYS)
+		else if (!pairwise &&
+			 key_idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 			key = rcu_dereference(sta->gtk[key_idx]);
 	} else
 		key = rcu_dereference(sdata->keys[key_idx]);