[Xcb] [PATCH] Avoid race condition when using multiple make jobs

[Donnie Berkholz]

Diego 'Flameeyes' Pettenò wrote:
> Also, use '$(LN_S) -f' rather than removing and recreating a file,
> that one should be as supported as 'rm -f' and requires one less command.

On some platforms including MSYS and old DJGPP, LN_S = `cp -p` so 
hopefully -f is a supported option everywhere to cp. It is in POSIX, FWIW.

Thanks,
Donnie