[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/paride/pcd.c b/drivers/block/paride/pcd.c
index 1eeb8f2..b8a994a 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -183,7 +183,7 @@
 static int pcd_detect(void);
 static void pcd_probe_capabilities(void);
 static void do_pcd_read_drq(void);
-static void do_pcd_request(request_queue_t * q);
+static void do_pcd_request(struct request_queue * q);
 static void do_pcd_read(void);
 
 struct pcd_unit {
@@ -713,7 +713,7 @@
 /* I/O request processing */
 static struct request_queue *pcd_queue;
 
-static void do_pcd_request(request_queue_t * q)
+static void do_pcd_request(struct request_queue * q)
 {
 	if (pcd_busy)
 		return;