code review 5372080: syscall: use error

src/pkg/net/interface_windows.go

 // Copyright 2011 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // Network interface identification for Windows
 
 package net
 
 import (
         "os"
@@ skipping 21 matching lines @@
                 e = syscall.GetAdaptersInfo(a, &l)
         }
         if e != 0 {
                 return nil, os.NewSyscallError("GetAdaptersInfo", e)
         }
         return a, nil
 }
 
 func getInterfaceList() ([]syscall.InterfaceInfo, error) {
         s, e := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
-        if e != 0 {
+        if e != nil {
                 return nil, os.NewSyscallError("Socket", e)
         }
         defer syscall.Closesocket(s)
 
         ii := [20]syscall.InterfaceInfo{}
         ret := uint32(0)
         size := uint32(unsafe.Sizeof(ii))
         e = syscall.WSAIoctl(s, syscall.SIO_GET_INTERFACE_LIST, nil, 0, (*byte)(unsafe.Pointer(&ii[0])), size, &ret, nil, 0)
-        if e != 0 {
+        if e != nil {
                 return nil, os.NewSyscallError("WSAIoctl", e)
         }
         c := ret / uint32(unsafe.Sizeof(ii[0]))
         return ii[:c-1], nil
 }
 
 // If the ifindex is zero, interfaceTable returns mappings of all
 // network interfaces.  Otheriwse it returns a mapping of a specific
 // interface.
 func interfaceTable(ifindex int) ([]Interface, error) {
@@ skipping 87 matching lines @@
         }
         return ifat, nil
 }
 
 // If the ifindex is zero, interfaceMulticastAddrTable returns
 // addresses for all network interfaces.  Otherwise it returns
 // addresses for a specific interface.
 func interfaceMulticastAddrTable(ifindex int) ([]Addr, error) {
         return nil, nil
 }