[BLOCK] Get rid of request_queue_t typedef

Some of the code has been gradually transitioned to using the proper
struct request_queue, but there's lots left. So do a full sweet of
the kernel and get rid of this typedef and replace its uses with
the proper type.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 35765f6..4d8798b 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -621,7 +621,7 @@
 }
 
 static int
-dcssblk_make_request(request_queue_t *q, struct bio *bio)
+dcssblk_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct dcssblk_dev_info *dev_info;
 	struct bio_vec *bvec;