staging/lustre: Remove server-side changelog defines

CHANGELOG_MAGIC, CHANGELOG_MINMASK, CHANGELOG_ALLMASK,
CHANGELOG_DEFMASK and CHANGELOG_USER_PREFIX are all unused
on the client.

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>