The Xorg binary is missing the extension $(EXEEXT) in the makefile

The Xorg binary is missing the extension $(EXEEXT) in the makefile

This is not a problem on UNIX platforms, but on CYGWIN it creates a broken
link to Xorg rather than a link to Xorg.exe.

From the CYGWIN log on tinderbox, we can see that the executable Xorg.exe is
installed correctly. We can see the command used to create the link:

(cd /jhbuild/install/[...]/install/bin && rm -f X && ln -s Xorg X)

Note that the "relink" makefile target correctly appends $(EXEEXT) to Xorg.

Reviewed-By:  Matt Dew <marcoz@osource.org>
Signed-off-by: Gaetan Nadon <memsize@videotron.ca>
Signed-off-by: Keith Packard <keithp@keithp.com>