syscall: fix build for Sizeof change

R=ken2
CC=golang-dev
https://golang.org/cl/4635051

src/pkg/syscall/route_bsd.go

@@ -59,7 +59,7 @@ type RoutingMessage interface {
 	sockaddr() []Sockaddr
 }
 
-const anyMessageLen = unsafe.Sizeof(anyMessage{})
+const anyMessageLen = int(unsafe.Sizeof(anyMessage{}))
 
 type anyMessage struct {
 	Msglen  uint16

src/pkg/syscall/syscall_bsd.go

@@ -400,7 +400,7 @@ func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (errno int) {
 }
 
 func SetsockoptString(fd, level, opt int, s string) (errno int) {
-	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), len(s))
+	return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), uintptr(len(s)))
 }
 
 //sys recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, errno int)