virtio-blk: fix the list operation in virtio_blk_load().

Although it is really rare to get in to the while loop, the list
operation in the loop is obviously wrong.

Signed-off-by: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

hw/virtio-blk.c

diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index 75878eb..0bf929a 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -470,7 +470,7 @@
         VirtIOBlockReq *req = virtio_blk_alloc_request(s);
         qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
         req->next = s->rq;
-        s->rq = req->next;
+        s->rq = req;
     }
 
     return 0;