VMware: Disable suds caching

The default cache implementation in suds store pickled objects in a
predictable path in /tmp which could lead to attacks. This patch
turns off suds caching to address this security issue.

Conflicts:
        cinder/volume/drivers/vmware/pbm.py

Change-Id: I7daaa25a0677004e03896298e9c3026d5c33c6ac
Closes-Bug: #1341954
(cherry picked from commit 6a41fe9c5c98a14a355fa81b41aae2c4b0ce0a7b)
Merge "VMware: Disable suds caching" into stable/havana