Code review comments from pmooney (sundry), and igork (screwups in zonecfg refactoring)

@@ -61,11 +61,11 @@
 int     access(char *, int);
 int     alarm(int);
 int     auditsys(struct auditcalls *, rval_t *);
 int64_t brandsys(int, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t,
     uintptr_t);
-int     brk(caddr_t);
+intptr_t        brk(caddr_t);
 int     chdir(char *);
 int     chmod(char *, int);
 int     chown(char *, uid_t, gid_t);
 int     chroot(char *);
 int     cladm(int, int, void *);