block: move timeout field in struct request to pack better

After commit 64c7f1d1, we went from 1 to 2 holes in my
test setup. If we move the timeout field a bit, we remove
both of those holes and shrink struct request by 8 bytes.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

include/linux/blkdev.h

@@ -215,6 +215,8 @@ struct request {
 
 	unsigned short ioprio;
 
+	unsigned int timeout;
+
 	void *special;		/* opaque pointer available for LLD use */
 
 	int errors;
@@ -223,7 +225,6 @@ struct request {
 
 	unsigned long deadline;
 	struct list_head timeout_list;
-	unsigned int timeout;
 
 	/*
 	 * completion callback.