scsi: return blk_status_t from scsi_init_io and ->init_command

Replace the old BLKPREP_* values with the BLK_STS_ ones that they are
converted to later anyway.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h
index fae8b46..6dffa85 100644
--- a/include/scsi/scsi_driver.h
+++ b/include/scsi/scsi_driver.h
@@ -2,6 +2,7 @@
 #ifndef _SCSI_SCSI_DRIVER_H
 #define _SCSI_SCSI_DRIVER_H
 
+#include <linux/blk_types.h>
 #include <linux/device.h>
 
 struct module;
@@ -13,7 +14,7 @@ struct scsi_driver {
 	struct device_driver	gendrv;
 
 	void (*rescan)(struct device *);
-	int (*init_command)(struct scsi_cmnd *);
+	blk_status_t (*init_command)(struct scsi_cmnd *);
 	void (*uninit_command)(struct scsi_cmnd *);
 	int (*done)(struct scsi_cmnd *);
 	int (*eh_action)(struct scsi_cmnd *, int);