Revert "Allow deleting instances while uuid lock is held"

This reverts commit 08beabc5e0fc3fffc074a634040f5821d4d1d5f2.

This patch creates race condition issues in the Hyper-V driver
due to the fact that spawn, destroy and other methods have been
written with the instance lock in mind.

In this context, thread safety needs to be enforced where needed
in all drivers before this patch can be applied.

Sample Hyper-V CI log showing the error:
http://64.119.130.115/63217/7/Hyper-V/hv-compute2/nova-compute.log.gz

Partial-Bug: #1276772

Change-Id: I72fb1f9de7767b7206c5fa39b87216fa3f1b5c68
Merge "Revert "Allow deleting instances while uuid lock is held""