iwlagn: fix aggregation queue scheduler setup

iwlagn's hardware scheduler needs to be set up
with the right aggregation frame limit and
buffer sizes. To achieve this, we need to move
the hardware queue setup to when the session
becomes operational.

Tested-by: Daniel Halperin <dhalperi@cs.washington.edu>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index b57fbbf..8fdd174 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -3345,6 +3345,10 @@
 		}
 		break;
 	case IEEE80211_AMPDU_TX_OPERATIONAL:
+		buf_size = min_t(int, buf_size, LINK_QUAL_AGG_FRAME_LIMIT_DEF);
+
+		iwlagn_txq_agg_queue_setup(priv, sta, tid, buf_size);
+
 		/*
 		 * If the limit is 0, then it wasn't initialised yet,
 		 * use the default. We can do that since we take the