Update openstack/common/lockutils

The following commits are in this update:

79e6bc6 fix lockutils.lock() to make it thread-safe
ace5120 Add main() to lockutils that creates temp dir for locks
537d8e2 Allow lockutils to get lock_path conf from envvar
d498c42 Fix to properly log when we release a semaphore

Change-Id: Ida26987e8841d79f3d4627d7f46ab08eb59234ec
Merge "Update openstack/common/lockutils"