target: Cleanup unused se_task bits

This is a squashed version of the following se_task cleanup patches:

    target: remove the unused task_state_flags field in se_task
    target: remove the unused se_obj_ptr field in se_task
    target: remove the se_dev field in se_task

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index dcf93f8..21a3677 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -499,7 +499,7 @@
 static void iblock_bio_destructor(struct bio *bio)
 {
 	struct se_task *task = bio->bi_private;
-	struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
+	struct iblock_dev *ib_dev = task->task_se_cmd->se_dev->dev_ptr;
 
 	bio_free(bio, ib_dev->ibd_bio_set);
 }
@@ -507,7 +507,7 @@
 static struct bio *
 iblock_get_bio(struct se_task *task, sector_t lba, u32 sg_num)
 {
-	struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
+	struct iblock_dev *ib_dev = task->task_se_cmd->se_dev->dev_ptr;
 	struct iblock_req *ib_req = IBLOCK_REQ(task);
 	struct bio *bio;