mac80211: never pass NULL params to ieee80211_if_add()

This isn't really a problem now, but it means that the function
has a few NULL checks that are only relevant when coming from
the initial interface added in mac80211, and that's confusing.
Just pass non-NULL (but equivalently empty) in that case and
remove all the NULL checks.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/iface.c

@@ -1799,7 +1799,7 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 		}
 
 		ieee80211_assign_perm_addr(local, ndev->perm_addr, type);
-		if (params && is_valid_ether_addr(params->macaddr))
+		if (is_valid_ether_addr(params->macaddr))
 			memcpy(ndev->dev_addr, params->macaddr, ETH_ALEN);
 		else
 			memcpy(ndev->dev_addr, ndev->perm_addr, ETH_ALEN);
@@ -1868,11 +1868,9 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 	ieee80211_setup_sdata(sdata, type);
 
 	if (ndev) {
-		if (params) {
 		ndev->ieee80211_ptr->use_4addr = params->use_4addr;
 		if (type == NL80211_IFTYPE_STATION)
 			sdata->u.mgd.use_4addr = params->use_4addr;
-		}
 
 		ndev->features |= local->hw.netdev_features;
 

net/mac80211/main.c

@@ -1221,8 +1221,10 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	/* add one default STA interface if supported */
 	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION) &&
 	    !ieee80211_hw_check(hw, NO_AUTO_VIF)) {
+		struct vif_params params = {0};
+
 		result = ieee80211_if_add(local, "wlan%d", NET_NAME_ENUM, NULL,
-					  NL80211_IFTYPE_STATION, NULL);
+					  NL80211_IFTYPE_STATION, &params);
 		if (result)
 			wiphy_warn(local->hw.wiphy,
 				   "Failed to add default virtual iface\n");