rtw88: remove unused variable 'in_lps'

Unused, will not be used neither, because the hardware/firmware
can only support one vif for LPS currnetly. If there's more than
one vif, than driver will never enter LPS. So remove it.
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtw88/mac80211.c

@@ -158,7 +158,6 @@ static int rtw_ops_add_interface(struct ieee80211_hw *hw,
 	rtwvif->stats.rx_unicast = 0;
 	rtwvif->stats.tx_cnt = 0;
 	rtwvif->stats.rx_cnt = 0;
-	rtwvif->in_lps = false;
 	memset(&rtwvif->bfee, 0, sizeof(struct rtw_bfee));
 	rtwvif->conf = &rtw_vif_port[port];
 	rtw_txq_init(rtwdev, vif->txq);

drivers/net/wireless/realtek/rtw88/main.h

@@ -747,7 +747,6 @@ struct rtw_vif {
 	const struct rtw_vif_port *conf;
 
 	struct rtw_traffic_stats stats;
-	bool in_lps;
 
 	struct rtw_bfee bfee;
 };