nl80211: multicast_to_unicast can be changed while IFF_UP

There is no need to prevent toggling multicast_to_unicast while
interface is already up. This change simplifies reconfiguration
from hostapd.

Signed-off-by: Michael Braun <michael-dev@fami-braun.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

@@ -11804,9 +11804,6 @@ static int nl80211_set_multicast_to_unicast(struct sk_buff *skb,
 	const struct nlattr *nla;
 	bool enabled;
 
-	if (netif_running(dev))
-		return -EBUSY;
-
 	if (!rdev->ops->set_multicast_to_unicast)
 		return -EOPNOTSUPP;