lockutils: remove local usage
lockutils: remove local usage

This doesn't seem like it's used by anything any more, so let's just
remove this local usage altogether. This also drops the lock check from
RPC, which shouldn't be a problem considering that this library is
already deprecated altogether.

Change-Id: I87ff0338adcfa092fd21acad5cf41d5746be1efe

varunarya10/oslo.concurrency,openstack/oslo.concurrency,JioCloud/oslo.concurrency