mac80211_hwsim: fix incorrect dev_alloc_name failure goto

If dev_alloc_name fails, hwsim_mon's memory allocated in alloc_netdev
needs to be freed.
Change goto command in dev_alloc_name failure to out_free_mon in
order to perform free_netdev.
Signed-off-by: Michael Vassernis <michael.vassernis@tandemg.com>
Link: https://lore.kernel.org/r/20191003073049.3760-1-michael.vassernis@tandemg.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/mac80211_hwsim.c

@@ -4026,7 +4026,7 @@ static int __init init_mac80211_hwsim(void)
 	err = dev_alloc_name(hwsim_mon, hwsim_mon->name);
 	if (err < 0) {
 		rtnl_unlock();
-		goto out_free_radios;
+		goto out_free_mon;
 	}
 
 	err = register_netdevice(hwsim_mon);