e1000e: Fix e1000_check_for_copper_link_ich8lan return value.

e1000e_check_for_copper_link() and e1000_check_for_copper_link_ich8lan()
are the two functions that may be assigned to mac.ops.check_for_link when
phy.media_type == e1000_media_type_copper. Commit 19110cfbb34d ("e1000e:
Separate signaling for link check/link up") changed the meaning of the
return value of check_for_link for copper media but only adjusted the first
function. This patch adjusts the second function likewise.

Reported-by: Christian Hesse <list@eworm.de>
Reported-by: Gabriel C <nix.or.die@gmail.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=198047
Fixes: 19110cfbb34d ("e1000e: Separate signaling for link check/link up")
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Tested-by: Christian Hesse <list@eworm.de>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/ich8lan.c

@@ -1367,6 +1367,9 @@ out:
  *  Checks to see of the link status of the hardware has changed.  If a
  *  change in link status has been detected, then we read the PHY registers
  *  to get the current speed/duplex if link exists.
+ *
+ *  Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link
+ *  up).
  **/
 static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 {
@@ -1382,7 +1385,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 	 * Change or Rx Sequence Error interrupt.
 	 */
 	if (!mac->get_link_status)
-		return 0;
+		return 1;
 
 	/* First we want to see if the MII Status Register reports
 	 * link.  If so, then we want to get the current speed/duplex
@@ -1613,10 +1616,12 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 	 * different link partner.
 	 */
 	ret_val = e1000e_config_fc_after_link_up(hw);
-	if (ret_val)
+	if (ret_val) {
 		e_dbg("Error configuring flow control\n");
+		return ret_val;
+	}
 
-	return ret_val;
+	return 1;
 }
 
 static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter)