[kilo] refactoring & hardening the code base

[AmitKumarDas]

1/ do null check for data @@ check_for_setup_error
do null check for tsm_res

tsm_cmd = "listTsm"
data = self._api_request_for_cloudbyte(tsm_cmd, {})
tsm_res = data["listTsmResponse"].get('listTsm')

3/ @@ _get_tsm_details
do a null check for data
do a null check for datasetid & tsmid & throw exception if any one is None

17/ @@ create_volume_from_snapshot

Move below message to last
Add chap info to below message

LOG.info(
_LI("Created a clone [%(cb_clone)s] "
"at CloudByte snapshot path [%(cb_snap)s] "
"w.r.t parent OpenStack volume [%(stack_vol)s]."),
{'cb_clone': cloned_volume_name,
'cb_snap': cb_snapshot_path,
'stack_vol': parent_volume_id})

18/ @@ delete_snapshot

Mark below message as Warning

LOG.error(_LE("CloudByte snapshot information is not available"
" for OpenStack volume [%s]."), source_volume_id)

19/ @@ retype

null check for response
i.e.
response = self._api_request_for_cloudbyte(
'listFileSystem', list_file_sys_params)

null check for cb_volume_list

null check for qos group id before using below statement

update_qos_group_params['id'] = cb_volume.get('groupid')

Lets add the xx_id's that were updated in below message

LOG.info(_LI("Successfully updated CloudByte volume [%(cb_vol)s] "
"corresponding to OpenStack volume [%(ops_vol)s]."),
{'cb_vol': cb_volume_id, 'ops_vol': volume['id']})