ipv6: remove unnecessary sysSockoptLen type

Change-Id: I87887ea03c36ca7d26e1ab2cb55d723611c942a8
Reviewed-on: https://go-review.googlesource.com/21354
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/ipv6/syscall_linux_386.go b/ipv6/syscall_linux_386.go
index 82633a5..64a3c66 100644
--- a/ipv6/syscall_linux_386.go
+++ b/ipv6/syscall_linux_386.go
@@ -16,14 +16,14 @@
 
 func socketcall(call int, a0, a1, a2, a3, a4, a5 uintptr) (int, syscall.Errno)
 
-func getsockopt(fd, level, name int, v unsafe.Pointer, l *sysSockoptLen) error {
+func getsockopt(fd, level, name int, v unsafe.Pointer, l *uint32) error {
 	if _, errno := socketcall(sysGETSOCKOPT, uintptr(fd), uintptr(level), uintptr(name), uintptr(v), uintptr(unsafe.Pointer(l)), 0); errno != 0 {
 		return error(errno)
 	}
 	return nil
 }
 
-func setsockopt(fd, level, name int, v unsafe.Pointer, l sysSockoptLen) error {
+func setsockopt(fd, level, name int, v unsafe.Pointer, l uint32) error {
 	if _, errno := socketcall(sysSETSOCKOPT, uintptr(fd), uintptr(level), uintptr(name), uintptr(v), uintptr(l), 0); errno != 0 {
 		return error(errno)
 	}