Change the openvz driver compute_driver entry to match
all other compute drivers in nova.

Change-Id: Ic9ce4dae930d46a8ce0e64a984880d5603f84f85
Fixes: bug #1133397
Ignore autogenerated .prereqs.

Change-Id: I593d6bc7776d73e8dff6b9791242fdc3b18db338
Merge "Change the openvz driver compute_driver entry to match all other compute drivers in nova."