iwlegacy: use pci_dev->revision

Commit be663ab6 (iwlwifi: split the drivers for
agn and legacy devices 3945/4965) added code to read the 4965's revision ID from
the PCI configuration register while it's already stored by PCI subsystem in the
'revision' field of 'struct pci_dev'...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlegacy/iwl4965-base.c

@@ -3179,7 +3179,7 @@ static void iwl4965_hw_detect(struct iwl_priv *priv)
 {
 	priv->hw_rev = _iwl_legacy_read32(priv, CSR_HW_REV);
 	priv->hw_wa_rev = _iwl_legacy_read32(priv, CSR_HW_REV_WA_REG);
-	pci_read_config_byte(priv->pci_dev, PCI_REVISION_ID, &priv->rev_id);
+	priv->rev_id = priv->pci_dev->revision;
 	IWL_DEBUG_INFO(priv, "HW Revision ID = 0x%X\n", priv->rev_id);
 }