Add IsMigratableToCSI to volume plugin interface

pkg/volume/scaleio/sio_plugin.go

@@ -72,6 +72,10 @@ func (p *sioPlugin) CanSupport(spec *volume.Spec) bool {
 		(spec.Volume != nil && spec.Volume.ScaleIO != nil)
 }
 
+func (p *sioPlugin) IsMigratedToCSI() bool {
+	return false
+}
+
 func (p *sioPlugin) RequiresRemount() bool {
 	return false
 }