nl80211: fix logic inversion in start_nan()

Arend inadvertently inverted the logic while converting to
wdev_running(), fix that.

Fixes: 73c7da3dae ("cfg80211: add generic helper to check interface is running")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

@@ -10628,7 +10628,7 @@ static int nl80211_start_nan(struct sk_buff *skb, struct genl_info *info)
 	if (wdev->iftype != NL80211_IFTYPE_NAN)
 		return -EOPNOTSUPP;
 
-	if (!wdev_running(wdev))
+	if (wdev_running(wdev))
 		return -EEXIST;
 
 	if (rfkill_blocked(rdev->rfkill))