VMware: remove unused parameter from _wait_for_task

The patch set removes the instance_uuid parameter from the
_wait_for_task method. This parameter was not used. In certain cases
an arbitrary data structure was passed to the method.

Change-Id: Idc578d6e962a63ff6c3c39f42bb0d888c6d1c7fc
Merge "VMware: remove unused parameter from _wait_for_task"