wifi: cfg80211: set country_elem to NULL

The link loop will always have a valid link so that
it's always set, but static checkers don't always
see that, so set it to NULL explicitly.

Fixes: efbabc11 ("cfg80211: Indicate MLO connection info in connect and roam callbacks")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/sme.c

@@ -723,7 +723,7 @@ void __cfg80211_connect_result(struct net_device *dev,
 			       bool wextev)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
-	const struct element *country_elem;
+	const struct element *country_elem = NULL;
 	const u8 *country_data;
 	u8 country_datalen;
 #ifdef CONFIG_CFG80211_WEXT