[Bug other/102664] contrib/gcc-git-customization.sh uses echo -n, which isn't portable

[egallager at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102664

--- Comment #38 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Martin Liška from comment #37)
> I guess so.

Yep, I can confirm this is fixed now; thanks!