blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE

Make sure that RQF_TIMED_OUT is cleared when a request is reused
after a block driver timeout handler has returned BLK_EH_DONE.

Fixes: da661267

 ("blk-mq: don't time out requests again that are in the timeout handler")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Andrew Randrianasulu <randrianasulu@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>