iwlwifi: fix iwl_mac_add_interface handler

This patch fixes iwl_mac_add_interface.

1. Currently only one interface is supported, instead of silently retuning
 0 now it returns  -EOPNOTSUPP (By Johannes Berg)
2. It enables changing mac address from user space (By Ian Schram)

Signed-off-by: Tomas Winkler <tomas@localhost.localdomain>
Cc: Zhu Yi <yi.zhu@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: linux-wireless <linux-wireless@vger.kernel.org
Cc: Ian Schram <ischram@telenet.be>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl4965-base.c b/drivers/net/wireless/iwlwifi/iwl4965-base.c
index 0b22e01..22d3bbc 100644
--- a/drivers/net/wireless/iwlwifi/iwl4965-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl4965-base.c
@@ -7330,9 +7330,6 @@
 	DECLARE_MAC_BUF(mac);
 
 	IWL_DEBUG_MAC80211("enter: id %d, type %d\n", conf->if_id, conf->type);
-	if (conf->mac_addr)
-		IWL_DEBUG_MAC80211("enter: MAC %s\n",
-				   print_mac(mac, conf->mac_addr));
 
 	if (priv->interface_id) {
 		IWL_DEBUG_MAC80211("leave - interface_id != 0\n");
@@ -7345,6 +7342,11 @@
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	mutex_lock(&priv->mutex);
+
+	if (conf->mac_addr) {
+		IWL_DEBUG_MAC80211("Set %s\n", print_mac(mac, conf->mac_addr));
+		memcpy(priv->mac_addr, conf->mac_addr, ETH_ALEN);
+	}
 	iwl_set_mode(priv, conf->type);
 
 	IWL_DEBUG_MAC80211("leave\n");