net: use IFF_* consts from package syscall on solaris

All necessary IFF_* consts are available in the syscall package. Use
them in linkFlags instead of duplicating them.

Change-Id: Ibd2b0f6f39f98bfad2a0c8c55d1eb64167aeee03
Reviewed-on: https://go-review.googlesource.com/c/go/+/255497
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/net/interface_solaris.go b/src/net/interface_solaris.go
index 5f9367f..f8d1571 100644
--- a/src/net/interface_solaris.go
+++ b/src/net/interface_solaris.go
@@ -32,39 +32,21 @@
 	return ift, nil
 }
 
-const (
-	sysIFF_UP          = 0x1
-	sysIFF_BROADCAST   = 0x2
-	sysIFF_DEBUG       = 0x4
-	sysIFF_LOOPBACK    = 0x8
-	sysIFF_POINTOPOINT = 0x10
-	sysIFF_NOTRAILERS  = 0x20
-	sysIFF_RUNNING     = 0x40
-	sysIFF_NOARP       = 0x80
-	sysIFF_PROMISC     = 0x100
-	sysIFF_ALLMULTI    = 0x200
-	sysIFF_INTELLIGENT = 0x400
-	sysIFF_MULTICAST   = 0x800
-	sysIFF_MULTI_BCAST = 0x1000
-	sysIFF_UNNUMBERED  = 0x2000
-	sysIFF_PRIVATE     = 0x8000
-)
-
 func linkFlags(rawFlags int) Flags {
 	var f Flags
-	if rawFlags&sysIFF_UP != 0 {
+	if rawFlags&syscall.IFF_UP != 0 {
 		f |= FlagUp
 	}
-	if rawFlags&sysIFF_BROADCAST != 0 {
+	if rawFlags&syscall.IFF_BROADCAST != 0 {
 		f |= FlagBroadcast
 	}
-	if rawFlags&sysIFF_LOOPBACK != 0 {
+	if rawFlags&syscall.IFF_LOOPBACK != 0 {
 		f |= FlagLoopback
 	}
-	if rawFlags&sysIFF_POINTOPOINT != 0 {
+	if rawFlags&syscall.IFF_POINTOPOINT != 0 {
 		f |= FlagPointToPoint
 	}
-	if rawFlags&sysIFF_MULTICAST != 0 {
+	if rawFlags&syscall.IFF_MULTICAST != 0 {
 		f |= FlagMulticast
 	}
 	return f