iwlwifi: create iwl_mac80211 unregister routine

The mac80211 setup_register operations are collected in one routine,
but the cleanup routines are not.  Create a routine for this.

Signed-off-by: Don Fry <donald.h.fry@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 5a9370d..f7e089d 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -1915,12 +1915,7 @@
 	set_bit(STATUS_EXIT_PENDING, &priv->shrd->status);
 
 	iwl_testmode_cleanup(priv);
-	iwl_leds_exit(priv);
-
-	if (priv->mac80211_registered) {
-		ieee80211_unregister_hw(priv->hw);
-		priv->mac80211_registered = 0;
-	}
+	iwlagn_mac_unregister(priv);
 
 	iwl_tt_exit(priv);