check the value of the configuration item retries

[zhangtralon]

we need to to check the value of the configuration item block_device_retries in the code in order to ensure the "block_device_retries " equal or bigger than 1 , done like that the configuration item network_allocate_retries

=====================
In ceilometer, there are similar issues, there is no check for value of retries
ceilometer.storage.mongo.utils.ConnectionPool#_mongo_connect
and:
ceilometer.ipmi.platform.intel_node_manager.NodeManager#init_node_manager

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/118005

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/118005
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=3d5cb0facecf62d9577ead6e129e83a2c4509273
Submitter: Jenkins
Branch: master

commit 3d5cb0facecf62d9577ead6e129e83a2c4509273
Author: zhangtralon <email address hidden>
Date: Sun Aug 31 10:55:39 2014 +0800

    check the block_device_allocate_retries

    we need to check the value of the configuration item
    block_device_allocate_retries in order to ensure to
    retry at least once,done like that configuration
    item network_allocate_retries

    Change-Id: Ia5b65bd160cb4e740d21c1b51d234e14e33135e7
    Closes-Bug:#1363558