mac80211_hwsim: fix possible memory leak in hwsim_new_radio_nl()

'hwname' is malloced in hwsim_new_radio_nl() and should be freed
before leaving from the error handling cases, otherwise it will cause
memory leak.

Fixes: ff4dd73dd2b4 ("mac80211_hwsim: check HWSIM_ATTR_RADIO_NAME length")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
static void mac80211_hwsim_change_chanctx(struct ieee80211_hw *hw,
					  struct ieee80211_chanctx_conf *ctx,
					  u32 changed)
{
	hwsim_check_chanctx_magic(ctx);
	wiphy_dbg(hw->wiphy,
		  "change channel context control: %d MHz/width: %d/cfreqs:%d/%d MHz\n",
		  ctx->def.chan->center_freq, ctx->def.width,
		  ctx->def.center_freq1, ctx->def.center_freq2);
}

static void mac80211_hwsim_change_chanctx(struct ieee80211_hw *hw,
					  struct ieee80211_chanctx_conf *ctx,
					  u32 changed)
{
	hwsim_check_chanctx_magic(ctx);
	wiphy_dbg(hw->wiphy,
		  "change channel context control: %d MHz/width: %d/cfreqs:%d/%d MHz\n",
		  ctx->def.chan->center_freq, ctx->def.width,
		  ctx->def.center_freq1, ctx->def.center_freq2);
}
