Description of problem:
lock_path does not have sane default value.

All other openstack package knows which directory
created by the rpm for state data, but looks like manila does not.

Version-Release number of selected component (if applicable):
python-manila-2.0.0-0.1.0rc1.el7.noarch

Actual results:
2016-04-07 09:18:45.571 19094 ERROR oslo_messaging.rpc.dispatcher     lock_file_path = _get_lock_path(name, lock_file_prefix, lock_path)
2016-04-07 09:18:45.571 19094 ERROR oslo_messaging.rpc.dispatcher   File "/usr/lib/python2.7/site-packages/oslo_concurrency/lockutils.py", line 140, in _get_lock_path
2016-04-07 09:18:45.571 19094 ERROR oslo_messaging.rpc.dispatcher     raise cfg.RequiredOptError('lock_path')
2016-04-07 09:18:45.571 19094 ERROR oslo_messaging.rpc.dispatcher RequiredOptError: value required for option: lock_path
2016-04-07 09:18:45.571 19094 ERROR oslo_messaging.rpc.dispatcher 


Expected results:
The directory created for state data is used by default.

/usr/share/manila/manila-dist.conf:
[DEFAULT]
state_path = /var/lib/manila
rootwrap_config = /etc/manila/rootwrap.conf
[oslo_concurrency]
lock_path = $state_path/tmp

(Currently the manila-dist.conf just has one comment line.)

Additional info:
lock_path = $state_path/lock could be used if the package would create this directory,but $state_path/tmp also sounds good.

rootwrap_config = /etc/manila/rootwrap.conf also needs to be in the manila-dist.conf .