wifi: nl80211: remove redundant err variable

Return value from rdev_set_mcast_rate() directly instead of
taking this in another redundant variable.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Jinpeng Cui <cui.jinpeng2@zte.com.cn>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

@@ -11279,7 +11279,6 @@ static int nl80211_set_mcast_rate(struct sk_buff *skb, struct genl_info *info)
 	struct net_device *dev = info->user_ptr[1];
 	int mcast_rate[NUM_NL80211_BANDS];
 	u32 nla_rate;
-	int err;
 
 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_ADHOC &&
 	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT &&
@@ -11298,9 +11297,7 @@ static int nl80211_set_mcast_rate(struct sk_buff *skb, struct genl_info *info)
 	if (!nl80211_parse_mcast_rate(rdev, mcast_rate, nla_rate))
 		return -EINVAL;
 
-	err = rdev_set_mcast_rate(rdev, dev, mcast_rate);
-
-	return err;
+	return rdev_set_mcast_rate(rdev, dev, mcast_rate);
 }
 
 static struct sk_buff *