[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/Documentation/block/request.txt b/Documentation/block/request.txt
index 75924e2..fff58acb 100644
--- a/Documentation/block/request.txt
+++ b/Documentation/block/request.txt
@@ -83,6 +83,6 @@
 
 struct bio *biotail		DBI	Last bio in request
 
-request_queue_t *q		DB	Request queue this request belongs to
+struct request_queue *q		DB	Request queue this request belongs to
 
 struct request_list *rl		B	Request list this request came from