ixgbe: using is_zero_ether_addr() to simplify the code

Using is_zero_ether_addr() to simplify the code.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_common.c

@@ -1778,8 +1778,7 @@ s32 ixgbe_validate_mac_addr(u8 *mac_addr)
 	else if (IXGBE_IS_BROADCAST(mac_addr))
 		status = IXGBE_ERR_INVALID_MAC_ADDR;
 	/* Reject the zero address */
-	else if (mac_addr[0] == 0 && mac_addr[1] == 0 && mac_addr[2] == 0 &&
-	         mac_addr[3] == 0 && mac_addr[4] == 0 && mac_addr[5] == 0)
+	else if (is_zero_ether_addr(mac_addr))
 		status = IXGBE_ERR_INVALID_MAC_ADDR;
 
 	return status;