block: disable I/O limits at the beginning of bdrv_close()

Disabling I/O limits from a BDS also drains all pending throttled
requests, so it should be done at the beginning of bdrv_close() with
the rest of the bdrv_drain() calls before the BlockDriver is closed.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

@@ -1907,6 +1907,12 @@ void bdrv_close(BlockDriverState *bs)
     if (bs->job) {
         block_job_cancel_sync(bs->job);
     }
+
+    /* Disable I/O limits and drain all pending throttled requests */
+    if (bs->io_limits_enabled) {
+        bdrv_io_limits_disable(bs);
+    }
+
     bdrv_drain(bs); /* complete I/O */
     bdrv_flush(bs);
     bdrv_drain(bs); /* in case flush left pending I/O */
@@ -1958,11 +1964,6 @@ void bdrv_close(BlockDriverState *bs)
         blk_dev_change_media_cb(bs->blk, false);
     }
 
-    /*throttling disk I/O limits*/
-    if (bs->io_limits_enabled) {
-        bdrv_io_limits_disable(bs);
-    }
-
     QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
         g_free(ban);
     }