rtlwifi: Remove set but not used variable 'rtstate'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/wireless/realtek/rtlwifi/ps.c: In function rtl_ps_set_rf_state:
drivers/net/wireless/realtek/rtlwifi/ps.c:71:19: warning: variable rtstate set but not used [-Wunused-but-set-variable]

It is not used since commit f1d2b4d3 ("rtlwifi:
rtl818x: Move drivers into new realtek directory")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtlwifi/ps.c

@@ -68,7 +68,6 @@ static bool rtl_ps_set_rf_state(struct ieee80211_hw *hw,
 {
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 	struct rtl_ps_ctl *ppsc = rtl_psc(rtl_priv(hw));
-	enum rf_pwrstate rtstate;
 	bool actionallowed = false;
 	u16 rfwait_cnt = 0;
 
@@ -102,8 +101,6 @@ static bool rtl_ps_set_rf_state(struct ieee80211_hw *hw,
 		}
 	}
 
-	rtstate = ppsc->rfpwr_state;
-
 	switch (state_toset) {
 	case ERFON:
 		ppsc->rfoff_reason &= (~changesource);