Assuming you have shared storage, you could power off vcenter and then browse to the IP address of one of the already updated hosts and register vCenter there. This would allow you to patch your host that vCenter was residing on.
1. Shutdown vCenter and remove from inventory.
2. Browse to IP of host you want to move vcenter to
3. From host you want to move vcenter to, browse datastore it resides on, find .vmx file right click and register VM.
4. Put it on one of your other hosts and power on.
5. Patch host that vcenter used to reside on.