block: Pass driver-specific options to .bdrv_refresh_filename()

In order to decide whether a blkdebug: filename can be produced or a
json: one is necessary, blkdebug checked whether bs->options had more
options than just "config", "x-image" or "image" (the latter including
nested options). That doesn't work well when generic block layer options
are present.

This patch passes an option QDict to the driver that contains only
driver-specific options, i.e. the options for the general block layer as
well as child nodes are already filtered out. Works much better this
way.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
diff --git a/block.c b/block.c
index fa351ac..c204d13 100644
--- a/block.c
+++ b/block.c
@@ -4027,7 +4027,10 @@
             bs->full_open_options = NULL;
         }
 
-        drv->bdrv_refresh_filename(bs);
+        opts = qdict_new();
+        append_open_options(opts, bs);
+        drv->bdrv_refresh_filename(bs, opts);
+        QDECREF(opts);
     } else if (bs->file) {
         /* Try to reconstruct valid information from the underlying file */
         bool has_open_options;