Remove w/COPYING and w/CREDITS dead symlinks

Not sure how useful these were to be exposed. But considering
they were added on purpose, maybe we should add the new versions
of these. Or add redirects, or keep back-compat symlinks.

For now, removing the dead symlinks.

Change-Id: I6594bc82b9de3f52a38e896db3f8dbfbda2ebed2