UFS: add const to parser token table

This patch adds a "const" to the parser token table. I've done an
allmodconfig build to see if this produces any warnings/failures and the
patch includes a fix for the only warning that was produced.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Alexander Viro <aviro@redhat.com>
Acked-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>