block: blk_rq_[cur_]_{sectors|bytes}() usage cleanup

With the previous changes, the followings are now guaranteed for all
requests in any valid state.

* blk_rq_sectors() == blk_rq_bytes() >> 9
* blk_rq_cur_sectors() == blk_rq_cur_bytes() >> 9

Clean up accessor usages.  Notable changes are

* nbd,i2o_block: end_all used instead of explicit byte count
* scsi_lib: unnecessary conditional on request type removed

[ Impact: cleanup ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/sbus/char/jsflash.c b/drivers/sbus/char/jsflash.c
index 2132c90..d56ddaa 100644
--- a/drivers/sbus/char/jsflash.c
+++ b/drivers/sbus/char/jsflash.c
@@ -189,7 +189,7 @@
 	while ((req = elv_next_request(q)) != NULL) {
 		struct jsfd_part *jdp = req->rq_disk->private_data;
 		unsigned long offset = blk_rq_pos(req) << 9;
-		size_t len = blk_rq_cur_sectors(req) << 9;
+		size_t len = blk_rq_cur_bytes(req);
 
 		if ((offset + len) > jdp->dsize) {
 			__blk_end_request_cur(req, -EIO);