Sync prototype with <unistd.h> (which DTRT all the time).

lib/libc/gen/valloc.3

@@ -1,4 +1,4 @@
-.\"	$NetBSD: valloc.3,v 1.4 1998/02/05 18:48:25 perry Exp $
+.\"	$NetBSD: valloc.3,v 1.5 1998/02/12 20:18:23 kleink Exp $
 .\"
 .\" Copyright (c) 1980, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -43,8 +43,8 @@
 .Lb libc
 .Sh SYNOPSIS
 .Fd #include <unistd.h>
-.Ft char *
-.Fn valloc "unsigned size"
+.Ft void *
+.Fn valloc "size_t size"
 .Sh DESCRIPTION
 .Bf -symbolic
 Valloc is obsoleted by the current version of malloc(3),