rtlwifi: avoid accessing RCR directly

The rtl*_set_check_bssid functions are mostly the same, but access the
RCR register in different ways. Use the get_hw_reg abstraction layer
(which reads rtlpci->receive_config for PCI devices and mac->rx_conf for
USB).

There is no functional change for cases where receive_config was
accessed directly. For rtl8192ce, there is still no change because
nothing modifies REG_RCR or receive_config. For rtl8192cu, it now also
applies changes to rx_conf from configure_filter, but that can be
considered a bug which is fixed later.

Signed-off-by: Peter Wu <lekensteyn@gmail.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rtlwifi/rtl8723ae/hw.c

@@ -1112,12 +1112,13 @@ static int _rtl8723ae_set_media_status(struct ieee80211_hw *hw,
 void rtl8723ae_set_check_bssid(struct ieee80211_hw *hw, bool check_bssid)
 {
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
-	struct rtl_pci *rtlpci = rtl_pcidev(rtl_pcipriv(hw));
-	u32 reg_rcr = rtlpci->receive_config;
+	u32 reg_rcr;
 
 	if (rtlpriv->psc.rfpwr_state != ERFON)
 		return;
 
+	rtlpriv->cfg->ops->get_hw_reg(hw, HW_VAR_RCR, (u8 *)(&reg_rcr));
+
 	if (check_bssid == true) {
 		reg_rcr |= (RCR_CBSSID_DATA | RCR_CBSSID_BCN);
 		rtlpriv->cfg->ops->set_hw_reg(hw, HW_VAR_RCR,