Change in vdsm[master]: lease: Add lease.find_device helper

[Code Review]

From Dan Kenigsberg :

Dan Kenigsberg has submitted this change and it was merged.

Change subject: lease: Add lease.find_device helper
......................................................................

lease: Add lease.find_device helper

Add a helper to lookup a lease device, similar to the helper for looking
up drives. This will be needed to located a lease device when hot
unplugging a lease.

Change-Id: I63c9d478330c5b91500b685313313c71a6202cc1
Bug-Url: https://bugzilla.redhat.com/1408825
Signed-off-by: Nir Soffer 
---
M lib/vdsm/virt/vmdevices/lease.py
M tests/virttests/vmlease_test.py
2 files changed, 70 insertions(+), 0 deletions(-)

Approvals:
  Nir Soffer: Verified
  Jenkins CI: Passed CI tests
  Dan Kenigsberg: Looks good to me, approved