Bugfix: pylint fix for yardstick/orchestrator/heat.py (no-value-for-parameter)

Bugfix: pylint fix for yardstick/orchestrator/heat.py (no-value-for-parameter)

Problem
op_utils.get_volume_id takes 2 arguments and only pass 1. This would
cause tc006 fail!
volume_id = op_utils.get_volume_id(volume_name)
it will cause:
Running pylint...
You can speed this up by running it on 'HEAD~[0-9]' (e.g. HEAD~0, this
change only)...
Using config file /home/opnfv/repos/yardstick/.pylintrc
************* Module yardstick.orchestrator.heat
E:235,20: No value for argument 'volume_name' in function call
(no-value-for-parameter)

To Do
It doesn't need to call get_volume_id here, just use heat get_resource
would be enough. This fix should work with tc006 test case.

JIRA: YARDSTICK-1371

Change-Id: I913ffd085f742ae4464dbcc4269719e2c50e37b5
Signed-off-by: rexlee8776 <limingjiang@huawei.com>