target: remove the task_size field in struct se_task

Now that we don't split commands the size field in the task is always
equivalent to the one in the CDB, even in cases where we have two tasks
due to a BIDI transfer.  Just refer the the size in the command instead
of duplicating it in the 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_pscsi.c b/drivers/target/target_core_pscsi.c
index 94c7a46..46eb017 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -967,8 +967,8 @@
 	struct bio *bio = NULL, *tbio = NULL;
 	struct page *page;
 	struct scatterlist *sg;
-	u32 data_len = task->task_size, i, len, bytes, off;
-	int nr_pages = (task->task_size + task_sg[0].offset +
+	u32 data_len = cmd->data_length, i, len, bytes, off;
+	int nr_pages = (cmd->data_length + task_sg[0].offset +
 			PAGE_SIZE - 1) >> PAGE_SHIFT;
 	int nr_vecs = 0, rc;
 	int rw = (task->task_data_direction == DMA_TO_DEVICE);
@@ -1085,7 +1085,7 @@
 			return -ENODEV;
 		}
 	} else {
-		BUG_ON(!task->task_size);
+		BUG_ON(!cmd->data_length);
 
 		/*
 		 * Setup the main struct request for the task->task_sg[] payload