pbr.version.VersionInfo needs package name (oslo.xyz and not oslo_xyz)

 We need to pass into VersionInfo what one would expect from running:
 setup.py --name

 Right now we pass in say oslo_context and pbr fails if there is no .git in
  the python source tree

  Closes-Bug: #1662266

Change-Id: I6bb3594ad625e0538cc8c654d679886b8302719a

oslo_concurrency/version.py

@@ -15,4 +15,4 @@
 
 import pbr.version
 
-version_info = pbr.version.VersionInfo('oslo_concurrency')
+version_info = pbr.version.VersionInfo('oslo.concurrency')