VMware: validate the network_info is defined

Ensure that the network info is defined correctly prior to allocating
networks.

Commit 6fb9cc8b278ceab05e65e1c5145141203211d246 caused a degradation.

Change-Id: I74eddc0ff744ee5d80df825a52527c67583bacea
Merge "VMware: validate the network_info is defined"