You can also try to cancel the vMotion tasks.
Not sure if this will work in all situations though.
I have no clue what a management agent restart will do with a running vMotion.
I would not try it, you might corrupt the VM involved.
Btw, in future you could also disable automatic mode for DRS when doing this in a cluster.
You maintenance mode vMotion might need to be confirmed, but there will not be any VMs being vMotioned back when you cancel the maintenace mode task.