lib/textsearch.c: remove textsearch_put reference from comments

There is no textsearch_put().  Remove it from the comments to avoid
misunderstanding.  Textsearch prepare no longer needs textsearch_put().

Signed-off-by: Raphael Silva <rapphil@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>