Revert "Revert "lock.py: is_vpm should test is_vm""
Revert "Revert "lock.py: is_vpm should test is_vm""

This reverts commit 097e11c04a40e013e91a7a64836c98413af6a71a.

I misidentified this as the commit which introduced a bug on Friday.
Reintroduce the original, innocent commit.

Signed-off-by: Zack Cerza <d7cdf09fc0f0426e98c9978ee42da5d61fa54986@redhat.com>

ktdreyer/teuthology,michaelsevilla/teuthology,ivotron/teuthology,robbat2/teuthology,dreamhost/teuthology,caibo2014/teuthology,dmick/teuthology,caibo2014/teuthology,michaelsevilla/teuthology,dreamhost/teuthology,dmick/teuthology,SUSE/teuthology,dmick/teuthology,SUSE/teuthology,SUSE/teuthology,robbat2/teuthology,ivotron/teuthology,ceph/teuthology,ceph/teuthology,ktdreyer/teuthology