sysctl move to /sbin

[itojun%iijlab.net@localhost]

>> Log Message:
>> move sysctl to /sbin/sysctl.  symlink from /usr/sbin/sysctl
>> is supplied for backward compatibility.
>I don't think that symlink should be made. We haven't done this in the
>past. (Rather, add /usr/sbin/sysctl to the "obsoleted"(?) list)

        I did not want to see breakage in user scripts.  I can remove
        symlink if many people thinks it better to.

itojun