CSI: fix early return on error from list external volumes command

If a plugin returns an error, we should continue at the outer scope to query
the next plugin, otherwise we just retry the plugin we got an error
on (potentially infinitely if it's an invalid request like an unsupported
plugin).

command/volume_status_csi.go

@@ -96,6 +96,7 @@ func (c *VolumeStatusCommand) listVolumes(client *api.Client) int {
 	var code int
 	q := &api.QueryOptions{PerPage: 30} // TODO: tune page size
 
+NEXT_PLUGIN:
 	for _, plugin := range plugins {
 		if !plugin.ControllerRequired || plugin.ControllersHealthy < 1 {
 			continue // only controller plugins can support this query
@@ -109,7 +110,7 @@ func (c *VolumeStatusCommand) listVolumes(client *api.Client) int {
 				// query, so report and set the error code but move on to the
 				// next plugin
 				code = 1
-				continue
+				continue NEXT_PLUGIN
 			}
 			rows := []string{}
 			if len(externalList.Volumes) > 0 {