cmd/fix: revert IPv6 scoped address zone support of IPNet

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7554051
diff --git a/src/cmd/fix/netipv6zone.go b/src/cmd/fix/netipv6zone.go
index bbaf5fc..fe973a2 100644
--- a/src/cmd/fix/netipv6zone.go
+++ b/src/cmd/fix/netipv6zone.go
@@ -14,7 +14,7 @@
 	"netipv6zone",
 	"2012-11-26",
 	netipv6zone,
-	`Adapt element key to IPNet, IPAddr, UDPAddr or TCPAddr composite literals.
+	`Adapt element key to IPAddr, UDPAddr or TCPAddr composite literals.
 
 https://codereview.appspot.com/6849045/
 `,
@@ -39,7 +39,7 @@
 			return
 		}
 		switch ss := se.Sel.String(); ss {
-		case "IPNet", "IPAddr", "UDPAddr", "TCPAddr":
+		case "IPAddr", "UDPAddr", "TCPAddr":
 			for i, e := range cl.Elts {
 				if _, ok := e.(*ast.KeyValueExpr); ok {
 					break
@@ -51,21 +51,13 @@
 						Value: e,
 					}
 				case 1:
-					if ss == "IPNet" {
+					if e.(*ast.BasicLit).Value == "0" {
+						cl.Elts = append(cl.Elts[:i], cl.Elts[i+1:]...)
+					} else {
 						cl.Elts[i] = &ast.KeyValueExpr{
-							Key:   ast.NewIdent("Mask"),
+							Key:   ast.NewIdent("Port"),
 							Value: e,
 						}
-					} else {
-						if e.(*ast.BasicLit).Value == "0" {
-							cl.Elts = append(cl.Elts[:i], cl.Elts[i+1:]...)
-						} else {
-							cl.Elts[i] = &ast.KeyValueExpr{
-								Key:   ast.NewIdent("Port"),
-								Value: e,
-							}
-						}
-
 					}
 				}
 				fixed = true
diff --git a/src/cmd/fix/netipv6zone_test.go b/src/cmd/fix/netipv6zone_test.go
index 569363e..0fab0053 100644
--- a/src/cmd/fix/netipv6zone_test.go
+++ b/src/cmd/fix/netipv6zone_test.go
@@ -15,18 +15,11 @@
 
 import "net"
 
-var a = []struct {
-	*net.IPNet
-}{
-	&net.IPNet{net.ParseIP("2001:DB8::"), net.IPMask(net.ParseIP("ffff:ffff:ffff::"))},
-}
-
 func f() net.Addr {
-	b := net.IPNet{net.IPv4(127, 0, 0, 1), net.IPv4Mask(255, 0, 0, 0)}
-	c := &net.IPAddr{ip1}
+	a := &net.IPAddr{ip1}
 	sub(&net.UDPAddr{ip2, 12345})
-	d := &net.TCPAddr{IP: ip3, Port: 54321}
-	e := &net.TCPAddr{ip4, 0}
+	c := &net.TCPAddr{IP: ip3, Port: 54321}
+	d := &net.TCPAddr{ip4, 0}
 	return &net.TCPAddr{ip5}, nil
 }
 `,
@@ -34,18 +27,11 @@
 
 import "net"
 
-var a = []struct {
-	*net.IPNet
-}{
-	&net.IPNet{IP: net.ParseIP("2001:DB8::"), Mask: net.IPMask(net.ParseIP("ffff:ffff:ffff::"))},
-}
-
 func f() net.Addr {
-	b := net.IPNet{IP: net.IPv4(127, 0, 0, 1), Mask: net.IPv4Mask(255, 0, 0, 0)}
-	c := &net.IPAddr{IP: ip1}
+	a := &net.IPAddr{IP: ip1}
 	sub(&net.UDPAddr{IP: ip2, Port: 12345})
-	d := &net.TCPAddr{IP: ip3, Port: 54321}
-	e := &net.TCPAddr{IP: ip4}
+	c := &net.TCPAddr{IP: ip3, Port: 54321}
+	d := &net.TCPAddr{IP: ip4}
 	return &net.TCPAddr{IP: ip5}, nil
 }
 `,