Fixed wait for job completion in VMAX driver

The VMAX driver used non-thread-safe variables in the wait for job
completion routines, resulting in failures or timeouts during concurrent
operations. This patch fixed the problem.

Closes-Bug: #1393568
Change-Id: I444b961a6543886da35fb44127b1cf7c509ce8d8
Merge "Fixed wait for job completion in VMAX driver"