rtlwifi: Use PCI Express Capability accessors

Use PCI Express Capability access functions to simplify rtlwifi driver.

[bhelgaas: split iwlegacy, iwlwifi, rtlwifi into separate patches]
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

drivers/net/wireless/rtlwifi/pci.c

@@ -372,13 +372,11 @@ static void rtl_pci_parse_configuration(struct pci_dev *pdev,
 	struct rtl_pci_priv *pcipriv = rtl_pcipriv(hw);
 
 	u8 tmp;
-	int pos;
-	u8 linkctrl_reg;
+	u16 linkctrl_reg;
 
 	/*Link Control Register */
-	pos = pci_pcie_cap(pdev);
-	pci_read_config_byte(pdev, pos + PCI_EXP_LNKCTL, &linkctrl_reg);
-	pcipriv->ndis_adapter.linkctrl_reg = linkctrl_reg;
+	pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &linkctrl_reg);
+	pcipriv->ndis_adapter.linkctrl_reg = (u8)linkctrl_reg;
 
 	RT_TRACE(rtlpriv, COMP_INIT, DBG_TRACE, "Link Control Register =%x\n",
 		 pcipriv->ndis_adapter.linkctrl_reg);