blk-mq: fix iteration of busy bitmap

Commit 889fa31f00b2 was a bit too eager in reducing the loop count,
so we ended up missing queues in some configurations. Ensure that
our division rounds up, so that's not the case.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 889fa31f00b2 ("blk-mq: reduce unnecessary software queue looping")
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 8210e87..2056a99 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -13,7 +13,7 @@
 };
 
 struct blk_mq_ctxmap {
-	unsigned int map_size;
+	unsigned int size;
 	unsigned int bits_per_word;
 	struct blk_align_bitmap *map;
 };