[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/block/ataflop.c b/drivers/block/ataflop.c
index 14d6b94..94268c7 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -1466,7 +1466,7 @@
 }
 
 
-void do_fd_request(request_queue_t * q)
+void do_fd_request(struct request_queue * q)
 {
  	unsigned long flags;