block: add wbt_disable_default export for BFQ

This isn't unused, if BFQ is modular we get into trouble.

Fixes: b6676f653f ("block: remove a few unused exports")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2018-11-15 12:31:27 -07:00
commit e815f404af