Moving insignificant messages from error to warning in sriov_config.py
Moving insignificant messages from error to warning in sriov_config.py

As the messages from _wait_for_vf_creation() don't seem to be error
messages so just moving them to be warning

Change-Id: Ic573cab63c1168c2bc2bc50c1e20c87c88202692
Closes-Bug: #1833073

openstack/os-net-config