ixgbe: Use a signed type to hold error codes

Because error codes are negative, it only makes sense to
consistently use signed types when handling them. Also remove
some explicit comparisons with 0 on these variables.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
index 8a2be44..af828f8 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
@@ -317,14 +317,14 @@
  **/
 static s32 ixgbe_get_phy_id(struct ixgbe_hw *hw)
 {
-	u32 status;
+	s32 status;
 	u16 phy_id_high = 0;
 	u16 phy_id_low = 0;
 
 	status = hw->phy.ops.read_reg(hw, MDIO_DEVID1, MDIO_MMD_PMAPMD,
 				      &phy_id_high);
 
-	if (status == 0) {
+	if (!status) {
 		hw->phy.id = (u32)(phy_id_high << 16);
 		status = hw->phy.ops.read_reg(hw, MDIO_DEVID2, MDIO_MMD_PMAPMD,
 					      &phy_id_low);