net: remove unused Interface parameter

Found by github.com/mvdan/unparam.

Change-Id: I4795dd0221784d10cf7c9f7b84ea00787d5789f2
Reviewed-on: https://go-review.googlesource.com/37892Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/net/interface_linux.go

@@ -162,7 +162,7 @@ loop:
 				if err != nil {
 					return nil, os.NewSyscallError("parsenetlinkrouteattr", err)
 				}
-				ifa := newAddr(ifi, ifam, attrs)
+				ifa := newAddr(ifam, attrs)
 				if ifa != nil {
 					ifat = append(ifat, ifa)
 				}
@@ -172,7 +172,7 @@ loop:
 	return ifat, nil
 }
 
-func newAddr(ifi *Interface, ifam *syscall.IfAddrmsg, attrs []syscall.NetlinkRouteAttr) Addr {
+func newAddr(ifam *syscall.IfAddrmsg, attrs []syscall.NetlinkRouteAttr) Addr {
 	var ipPointToPoint bool
 	// Seems like we need to make sure whether the IP interface
 	// stack consists of IP point-to-point numbered or unnumbered