EQLX Driver: Refactor ssh code to common utils

[Rajini Karthik]

Equallogic driver has some code that can be moved to utils.

There is a very similar implementation of _run_ssh() in SanDriver: https://github.com/openstack/cinder/blob/master/cinder/volume/drivers/san/san.py#L104
I think, this function should be taken out and made available probably in processutils. so that it can be used by other drivers.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/203720

[OpenStack Infra (hudson-openstack)]

Change abandoned by Rajini Ram (<email address hidden>) on branch: master
Review: https://review.openstack.org/203720
Reason: he common processutils doesn't seem to work for equalogic cli. Have to stick back to paramiko custom implementation.
Abandoningg this review. Will submit a separate review for just deprecating eqlx_cli_timeout in favor of ssh_conn_timeout

[Rajini Karthik (rajini-karthik)]

This bug should be closed