[PATCH] remove unnecessary blk_queue_bounce in SG_IO

When I converted the original patch, I left unnecessary blk_queue_bounce in
SG_IO.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>