Pass no arguments to _wait_for_provision_state()

Commit 39e0a28d modified the inner function in destroy() to take
no arguments but its caller was not updated.  This avoids a TypeError
during Nova instance deletion.

Closes-Bug: #1296918
Change-Id: I865b1ef92b0a3736e0e6295892c663f7e4ab792e
Merge "Pass no arguments to _wait_for_provision_state()"