block: add flags to bdrv_*_write_zeroes

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 667f4e4..7e9fecb 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -442,7 +442,7 @@
     CoWriteZeroes *data = opaque;
 
     data->ret = bdrv_co_write_zeroes(data->bs, data->offset / BDRV_SECTOR_SIZE,
-                                     data->count / BDRV_SECTOR_SIZE);
+                                     data->count / BDRV_SECTOR_SIZE, 0);
     data->done = true;
     if (data->ret < 0) {
         *data->total = data->ret;