e1000: FIX: don't poke at manageability registers for incompatible adapters

The MANC register should not be read for PCI-E adapters at all, as well as
82543 and older where 82543 would master abort when this register was
accessed.

Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
diff --git a/drivers/net/e1000/e1000_ethtool.c b/drivers/net/e1000/e1000_ethtool.c
index 773821e..71fb278 100644
--- a/drivers/net/e1000/e1000_ethtool.c
+++ b/drivers/net/e1000/e1000_ethtool.c
@@ -461,7 +461,8 @@
 	regs_buff[24] = (uint32_t)phy_data;  /* phy local receiver status */
 	regs_buff[25] = regs_buff[24];  /* phy remote receiver status */
 	if (hw->mac_type >= e1000_82540 &&
-	   hw->media_type == e1000_media_type_copper) {
+	    hw->mac_type < e1000_82571 &&
+	    hw->media_type == e1000_media_type_copper) {
 		regs_buff[26] = E1000_READ_REG(hw, MANC);
 	}
 }