Description of problem:
There is a validation of macAddress field when creating VMs and it works good when both macs have same delimiter (e.g. ":"), when the mac already in use - second VM can't be created

But if the VMs have different macAddress delimiters (first ":", second "-") - the validation does not work
As result it is possible to have 2 VMIs with the same mac address:

> $ oc describe vmi vm-fedora | grep "Mac:"
> Mac: 02:f2:8c:00:00:1a
> $ oc describe vmi vm-fedora-2 | grep "Mac:"
> Mac: 02:f2:8c:00:00:1a

> [fedora@vm-fedora ~]$ ip a | grep ether
> link/ether 02:f2:8c:00:00:1a brd ff:ff:ff:ff:ff:ff

> [fedora@vm-fedora-2 ~]$ ip a | grep ether
> link/ether 02:f2:8c:00:00:1a brd ff:ff:ff:ff:ff:ff

Version-Release number of selected component (if applicable):
4.11

How reproducible:
100%

Steps to Reproduce:
1. create first VM with macAddress using ":" as delimiters (e.g. "02:f2:8c:00:00:1a")
2. create second VM with same macAddress but "-" as delimiter (e.g. "02-f2-8c-00-00-1a")
3.

Actual results:
Both VMs created

Expected results:
VMs with the same mac address should not be created.

Additional info: