patch to avoid race condition in rsync 2.5.6

[Petter Reinholdtsen]

[Wayne Davison]
> That patch was included in the 2.6.3pre1 release (though a small
> portion of it proved to be unneeded and was not applied).  See the
> rsync.samba.org web site for the source (and there's a debian release
> in experimental which has a version of 2.6.2.pre3.1-1 because the
> official version number would not sort prior to the final 2.6.3
> when it is released).

I tried to compile 2.6.3pre1 on all my archs, and it compiled out of
the box.  I tested on Solaris, AIX, Irix, HP-UX, Mac OS X, Linux and
Tru64 Unix (I hope I remember them all. :).

Good work. :)