mac80211_hwsim: fix a possible memory leak in hwsim_new_radio_nl()

'hwname' should be freed before leaving from the error handling cases,
otherwise it will cause mem leak

Fixes: cb1a5bae5684 ("mac80211_hwsim: add permanent mac address option for new radios")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/mac80211_hwsim.c

@@ -3236,6 +3236,7 @@ static int hwsim_new_radio_nl(struct sk_buff *msg, struct genl_info *info)
 			GENL_SET_ERR_MSG(info,"MAC is no valid source addr");
 			NL_SET_BAD_ATTR(info->extack,
 					info->attrs[HWSIM_ATTR_PERM_ADDR]);
+			kfree(hwname);
 			return -EINVAL;
 		}